How to Check Your PostgreSQL Version
New versions of PostgreSQL are released at regular intervals. Major releases are scheduled yearly and focus on improving key features and fixing known bugs. Minor releases are available approximately every three months and aim to resolve ongoing security concerns.
You might want to check if you have the latest security patch, or if the new software you want to implement is compatible with your PostgreSQL version.
This tutorial shows you how to check your PostgreSQL version using a few short commands.
Note: Have you considered installing SQL Workbench for Postgres? It’s a great tool for managing different database systems.
- Access to a terminal window/command line
- PostgreSQL database server
Check PostgreSQL Version from Command Line
Access your terminal and enter the following command to check your PostgreSQL version:
The version number is displayed in your terminal window. Another way to check your PostgreSQL version is to use the -V option:
These two commands work with installations initiated from official repositories. They might not be applicable for installations originating from third-party sources. Instead, you might receive the “Command ‘postgres’ not found” message.
How to Solve the “Command ‘postgres’ not found” Error
To solve the “Command ‘postgres’ not found” issue, locate the PostgreSQL binary folder. Enter the following command to locate the correct postgres path:
The path to your binary folder is now displayed in your terminal.
Type the full path and add the -V option to display the current PostgreSQL server version:
In this example, the Postgres version number is 10.12.
The PostgreSQL Development Group uses a standard MAJOR.MINOR semantic versioning system. In our example, the first section (10) signifies the MAJOR release number. The second part (12), represents the MINOR release number for that major version.
Note: Always update PostgreSQL to the latest available minor version that corresponds to the major version you have installed.
Check Postgres Version from SQL Shell
The version number can also be retrieved directly from the PostgreSQL prompt. Access the PostgreSQL shell prompt by typing the following command:
Type the following SQL statement within the prompt to check the current version:
The resulting output provides the full version and system information for the PostgreSQL server.
You can also instruct PostgreSQL to show the value associated with the server_version parameter:
The result displays the current value for server_version.
How to Check psql Client Version
Psql functions as a front-end terminal for PostgreSQL. It’s used to issue queries and display the provided results.
You can use the following command to determine the version of the psql client utility:
You’ll notice that the commands used to check the psql client version match the commands used to determine PostgreSQL server version. The -V option works in this instance as well:
The psql version is presented in the terminal.
The “Command not found” error can appear in this instance as well. If that is the case, enter the following command to locate the correct path to the psql utility:
The output provides the full path to the psql utility.
Use the resulting path and -V option to check the current psql version:
The resulting output shows you the current psql client version on your system.
Note: If you are in need of more PostgreSQL tutorials, be sure to check out:
The provided commands and SQL statements are the most effective way to determine the PostgreSQL version number. Use them to check the current version of your PostgreSQL database server or psql client utility.
Make sure that your systems are always up to date with the latest available version.
How to Check PostgreSQL Version
Earlier, its major version was represented as a decimal number, e.g., 9.6 or 9.0. After PostgreSQL 10, the central part of the version increased by one number for major release versions, e.g., 10, 11, 12, etc.
Minor Version of PostgreSQL
The last part number of the version shows the minor release number. E.g., 10.4 or 10.6 are minor versions of PostgreSQL version 10. In the past, Version 13.3 of PostgreSQL has been available for installation. We will explore different methods to check PostgreSQL’s version in this tutorial.
How to Check PostgreSQL Version
You can check the PostgreSQL version in several ways. Here, we will understand all the methods and see how you can check the version of PostgreSQL in your system.
Check the PostgreSQL Version Using Command-Line
You can check the current PostgreSQL version running on your system with the help of the command line. You can do this by accessing the terminal and running the following command:
You can run any of the previous commands and check the PostgreSQL version. Both the commands will provide you with the same output.
You get an error of “Postgres: command not found” if the Postgres binary is not present in the path to the file system. Let us troubleshoot this problem by searching the PostgreSQL binary directory. Run the following command in a terminal window:
With this command, you can see the full path to the PostgreSQL binary folder in your terminal. Type the full path to find out what version of PostgreSQL you have:
Both these commands will provide you with the same output.
Check the PostgreSQL Version Using SQL Shell
You can retrieve the PostgreSQL version through the PostgreSQL prompt. PostgreSQL versions are displayed on the post-login screen after logging into the PostgreSQL server through the terminal.
The server should log into the SQL prompt and get its output by executing the SQL command.
Through Parameters
You can check the PostgreSQL version by preset parameter. Automatic version checking is also possible using the following method:
Through version() Function
By executing version(), you can also determine the PostgreSQL version. You can also check the PostgreSQL version in the automation script.
Check the PostgreSQL Version PSQL Client Version
Apart from being a PostgreSQL client, psql is also a terminal-based command-line utility. Psql gives users access to PostgreSQL databases. Version information for the psql client utility can be found using the following command:
The previous commands will provide you with the same output to use by anyone.
Postgres Version in pgAdmin4
The pgAdmin4 web interface is an excellent way to manage PostgreSQL servers. The web interface shows the Postgres version for the pgAdmin4 users. To find out the PostgreSQL version, follow these steps:
- Login to the pgAdmin4.
- Select your Postgres server by expanding servers in the left sidebar.
- Now, go to the properties tab.
- The last step is to check the PostgreSQL version under the general section.
Conclusion
In this tutorial, we’ve discussed several methods to check the PostgreSQL version and see how easy it is to check each version. We hope that through this article, you have understood all the methods, and you will have learned to check the version of PostgreSQL by each method. Check the other Linux Hint articles for more tips and tutorials.
About the author
Prateek Jangid
A passionate Linux user for personal and professional reasons, always exploring what is new in the world of Linux and sharing with my readers.
Как узнать версию postgresql linux
Table 9.66 shows several functions that extract session and system information.
In addition to the functions listed in this section, there are a number of functions related to the statistics system that also provide system information. See Section 28.2.2 for more information.
Table 9.66. Session Information Functions
Returns the name of the current database. (Databases are called “ catalogs ” in the SQL standard, so current_catalog is the standard’s spelling.)
Returns the text of the currently executing query, as submitted by the client (which might contain more than one statement).
This is equivalent to current_user .
Returns the name of the schema that is first in the search path (or a null value if the search path is empty). This is the schema that will be used for any tables or other named objects that are created without specifying a target schema.
current_schemas ( include_implicit boolean ) → name[]
Returns an array of the names of all schemas presently in the effective search path, in their priority order. (Items in the current search_path setting that do not correspond to existing, searchable schemas are omitted.) If the Boolean argument is true , then implicitly-searched system schemas such as pg_catalog are included in the result.
Returns the user name of the current execution context.
Returns the IP address of the current client, or NULL if the current connection is via a Unix-domain socket.
Returns the IP port number of the current client, or NULL if the current connection is via a Unix-domain socket.
Returns the IP address on which the server accepted the current connection, or NULL if the current connection is via a Unix-domain socket.
Returns the IP port number on which the server accepted the current connection, or NULL if the current connection is via a Unix-domain socket.
Returns the process ID of the server process attached to the current session.
pg_blocking_pids ( integer ) → integer[]
Returns an array of the process ID(s) of the sessions that are blocking the server process with the specified process ID from acquiring a lock, or an empty array if there is no such server process or it is not blocked.
One server process blocks another if it either holds a lock that conflicts with the blocked process’s lock request (hard block), or is waiting for a lock that would conflict with the blocked process’s lock request and is ahead of it in the wait queue (soft block). When using parallel queries the result always lists client-visible process IDs (that is, pg_backend_pid results) even if the actual lock is held or awaited by a child worker process. As a result of that, there may be duplicated PIDs in the result. Also note that when a prepared transaction holds a conflicting lock, it will be represented by a zero process ID.
Frequent calls to this function could have some impact on database performance, because it needs exclusive access to the lock manager’s shared state for a short time.
pg_conf_load_time () → timestamp with time zone
Returns the time when the server configuration files were last loaded. If the current session was alive at the time, this will be the time when the session itself re-read the configuration files (so the reading will vary a little in different sessions). Otherwise it is the time when the postmaster process re-read the configuration files.
pg_current_logfile ( [ text ] ) → text
Returns the path name of the log file currently in use by the logging collector. The path includes the log_directory directory and the individual log file name. The result is NULL if the logging collector is disabled. When multiple log files exist, each in a different format, pg_current_logfile without an argument returns the path of the file having the first format found in the ordered list: stderr , csvlog , jsonlog . NULL is returned if no log file has any of these formats. To request information about a specific log file format, supply either csvlog , jsonlog or stderr as the value of the optional parameter. The result is NULL if the log format requested is not configured in log_destination. The result reflects the contents of the current_logfiles file.
Returns the OID of the current session’s temporary schema, or zero if it has none (because it has not created any temporary tables).
pg_is_other_temp_schema ( oid ) → boolean
Returns true if the given OID is the OID of another session’s temporary schema. (This can be useful, for example, to exclude other sessions’ temporary tables from a catalog display.)
Returns true if a JIT compiler extension is available (see Chapter 32) and the jit configuration parameter is set to on .
pg_listening_channels () → setof text
Returns the set of names of asynchronous notification channels that the current session is listening to.
pg_notification_queue_usage () → double precision
Returns the fraction (0–1) of the asynchronous notification queue’s maximum size that is currently occupied by notifications that are waiting to be processed. See LISTEN and NOTIFY for more information.
pg_postmaster_start_time () → timestamp with time zone
Returns the time when the server started.
pg_safe_snapshot_blocking_pids ( integer ) → integer[]
Returns an array of the process ID(s) of the sessions that are blocking the server process with the specified process ID from acquiring a safe snapshot, or an empty array if there is no such server process or it is not blocked.
A session running a SERIALIZABLE transaction blocks a SERIALIZABLE READ ONLY DEFERRABLE transaction from acquiring a snapshot until the latter determines that it is safe to avoid taking any predicate locks. See Section 13.2.3 for more information about serializable and deferrable transactions.
Frequent calls to this function could have some impact on database performance, because it needs access to the predicate lock manager’s shared state for a short time.
Returns the current nesting level of PostgreSQL triggers (0 if not called, directly or indirectly, from inside a trigger).
Returns the session user’s name.
This is equivalent to current_user .
Returns a string describing the PostgreSQL server’s version. You can also get this information from server_version, or for a machine-readable version use server_version_num. Software developers should use server_version_num (available since 8.2) or PQserverVersion instead of parsing the text version.
The session_user is normally the user who initiated the current database connection; but superusers can change this setting with SET SESSION AUTHORIZATION . The current_user is the user identifier that is applicable for permission checking. Normally it is equal to the session user, but it can be changed with SET ROLE . It also changes during the execution of functions with the attribute SECURITY DEFINER . In Unix parlance, the session user is the “ real user ” and the current user is the “ effective user ” . current_role and user are synonyms for current_user . (The SQL standard draws a distinction between current_role and current_user , but PostgreSQL does not, since it unifies users and roles into a single kind of entity.)
Table 9.67 lists functions that allow querying object access privileges programmatically. (See Section 5.7 for more information about privileges.) In these functions, the user whose privileges are being inquired about can be specified by name or by OID ( pg_authid . oid ), or if the name is given as public then the privileges of the PUBLIC pseudo-role are checked. Also, the user argument can be omitted entirely, in which case the current_user is assumed. The object that is being inquired about can be specified either by name or by OID, too. When specifying by name, a schema name can be included if relevant. The access privilege of interest is specified by a text string, which must evaluate to one of the appropriate privilege keywords for the object’s type (e.g., SELECT ). Optionally, WITH GRANT OPTION can be added to a privilege type to test whether the privilege is held with grant option. Also, multiple privilege types can be listed separated by commas, in which case the result will be true if any of the listed privileges is held. (Case of the privilege string is not significant, and extra whitespace is allowed between but not within privilege names.) Some examples:
Table 9.67. Access Privilege Inquiry Functions
has_any_column_privilege ( [ user name or oid , ] table text or oid , privilege text ) → boolean
Does user have privilege for any column of table? This succeeds either if the privilege is held for the whole table, or if there is a column-level grant of the privilege for at least one column. Allowable privilege types are SELECT , INSERT , UPDATE , and REFERENCES .
has_column_privilege ( [ user name or oid , ] table text or oid , column text or smallint , privilege text ) → boolean
Does user have privilege for the specified table column? This succeeds either if the privilege is held for the whole table, or if there is a column-level grant of the privilege for the column. The column can be specified by name or by attribute number ( pg_attribute . attnum ). Allowable privilege types are SELECT , INSERT , UPDATE , and REFERENCES .
has_database_privilege ( [ user name or oid , ] database text or oid , privilege text ) → boolean
Does user have privilege for database? Allowable privilege types are CREATE , CONNECT , TEMPORARY , and TEMP (which is equivalent to TEMPORARY ).
has_foreign_data_wrapper_privilege ( [ user name or oid , ] fdw text or oid , privilege text ) → boolean
Does user have privilege for foreign-data wrapper? The only allowable privilege type is USAGE .
has_function_privilege ( [ user name or oid , ] function text or oid , privilege text ) → boolean
Does user have privilege for function? The only allowable privilege type is EXECUTE .
When specifying a function by name rather than by OID, the allowed input is the same as for the regprocedure data type (see Section 8.19). An example is:
has_language_privilege ( [ user name or oid , ] language text or oid , privilege text ) → boolean
Does user have privilege for language? The only allowable privilege type is USAGE .
has_parameter_privilege ( [ user name or oid , ] parameter text , privilege text ) → boolean
Does user have privilege for configuration parameter? The parameter name is case-insensitive. Allowable privilege types are SET and ALTER SYSTEM .
has_schema_privilege ( [ user name or oid , ] schema text or oid , privilege text ) → boolean
Does user have privilege for schema? Allowable privilege types are CREATE and USAGE .
has_sequence_privilege ( [ user name or oid , ] sequence text or oid , privilege text ) → boolean
Does user have privilege for sequence? Allowable privilege types are USAGE , SELECT , and UPDATE .
has_server_privilege ( [ user name or oid , ] server text or oid , privilege text ) → boolean
Does user have privilege for foreign server? The only allowable privilege type is USAGE .
has_table_privilege ( [ user name or oid , ] table text or oid , privilege text ) → boolean
Does user have privilege for table? Allowable privilege types are SELECT , INSERT , UPDATE , DELETE , TRUNCATE , REFERENCES , and TRIGGER .
has_tablespace_privilege ( [ user name or oid , ] tablespace text or oid , privilege text ) → boolean
Does user have privilege for tablespace? The only allowable privilege type is CREATE .
has_type_privilege ( [ user name or oid , ] type text or oid , privilege text ) → boolean
Does user have privilege for data type? The only allowable privilege type is USAGE . When specifying a type by name rather than by OID, the allowed input is the same as for the regtype data type (see Section 8.19).
pg_has_role ( [ user name or oid , ] role text or oid , privilege text ) → boolean
Does user have privilege for role? Allowable privilege types are MEMBER and USAGE . MEMBER denotes direct or indirect membership in the role (that is, the right to do SET ROLE ), while USAGE denotes whether the privileges of the role are immediately available without doing SET ROLE . This function does not allow the special case of setting user to public , because the PUBLIC pseudo-role can never be a member of real roles.
row_security_active ( table text or oid ) → boolean
Is row-level security active for the specified table in the context of the current user and current environment?
Table 9.68 shows the operators available for the aclitem type, which is the catalog representation of access privileges. See Section 5.7 for information about how to read access privilege values.
Table 9.68. aclitem Operators
aclitem = aclitem → boolean
Are aclitem s equal? (Notice that type aclitem lacks the usual set of comparison operators; it has only equality. In turn, aclitem arrays can only be compared for equality.)
‘calvin=r*w/hobbes’::aclitem = ‘calvin=r*w*/hobbes’::aclitem → f
aclitem[] @> aclitem → boolean
Does array contain the specified privileges? (This is true if there is an array entry that matches the aclitem ‘s grantee and grantor, and has at least the specified set of privileges.)
This is a deprecated alias for @> .
Table 9.69 shows some additional functions to manage the aclitem type.
Table 9.69. aclitem Functions
acldefault ( type «char» , ownerId oid ) → aclitem[]
Constructs an aclitem array holding the default access privileges for an object of type type belonging to the role with OID ownerId . This represents the access privileges that will be assumed when an object’s ACL entry is null. (The default access privileges are described in Section 5.7.) The type parameter must be one of ‘c’ for COLUMN , ‘r’ for TABLE and table-like objects, ‘s’ for SEQUENCE , ‘d’ for DATABASE , ‘f’ for FUNCTION or PROCEDURE , ‘l’ for LANGUAGE , ‘L’ for LARGE OBJECT , ‘n’ for SCHEMA , ‘p’ for PARAMETER , ‘t’ for TABLESPACE , ‘F’ for FOREIGN DATA WRAPPER , ‘S’ for FOREIGN SERVER , or ‘T’ for TYPE or DOMAIN .
aclexplode ( aclitem[] ) → setof record ( grantor oid , grantee oid , privilege_type text , is_grantable boolean )
Returns the aclitem array as a set of rows. If the grantee is the pseudo-role PUBLIC, it is represented by zero in the grantee column. Each granted privilege is represented as SELECT , INSERT , etc. Note that each privilege is broken out as a separate row, so only one keyword appears in the privilege_type column.
makeaclitem ( grantee oid , grantor oid , privileges text , is_grantable boolean ) → aclitem
Constructs an aclitem with the given properties.
Table 9.70 shows functions that determine whether a certain object is visible in the current schema search path. For example, a table is said to be visible if its containing schema is in the search path and no table of the same name appears earlier in the search path. This is equivalent to the statement that the table can be referenced by name without explicit schema qualification. Thus, to list the names of all visible tables:
For functions and operators, an object in the search path is said to be visible if there is no object of the same name and argument data type(s) earlier in the path. For operator classes and families, both the name and the associated index access method are considered.
Table 9.70. Schema Visibility Inquiry Functions
pg_collation_is_visible ( collation oid ) → boolean
Is collation visible in search path?
pg_conversion_is_visible ( conversion oid ) → boolean
Is conversion visible in search path?
pg_function_is_visible ( function oid ) → boolean
Is function visible in search path? (This also works for procedures and aggregates.)
pg_opclass_is_visible ( opclass oid ) → boolean
Is operator class visible in search path?
pg_operator_is_visible ( operator oid ) → boolean
Is operator visible in search path?
pg_opfamily_is_visible ( opclass oid ) → boolean
Is operator family visible in search path?
pg_statistics_obj_is_visible ( stat oid ) → boolean
Is statistics object visible in search path?
pg_table_is_visible ( table oid ) → boolean
Is table visible in search path? (This works for all types of relations, including views, materialized views, indexes, sequences and foreign tables.)
pg_ts_config_is_visible ( config oid ) → boolean
Is text search configuration visible in search path?
pg_ts_dict_is_visible ( dict oid ) → boolean
Is text search dictionary visible in search path?
pg_ts_parser_is_visible ( parser oid ) → boolean
Is text search parser visible in search path?
pg_ts_template_is_visible ( template oid ) → boolean
Is text search template visible in search path?
pg_type_is_visible ( type oid ) → boolean
Is type (or domain) visible in search path?
All these functions require object OIDs to identify the object to be checked. If you want to test an object by name, it is convenient to use the OID alias types ( regclass , regtype , regprocedure , regoperator , regconfig , or regdictionary ), for example:
Note that it would not make much sense to test a non-schema-qualified type name in this way — if the name can be recognized at all, it must be visible.
Table 9.71 lists functions that extract information from the system catalogs.
Table 9.71. System Catalog Information Functions
format_type ( type oid , typemod integer ) → text
Returns the SQL name for a data type that is identified by its type OID and possibly a type modifier. Pass NULL for the type modifier if no specific modifier is known.
pg_char_to_encoding ( encoding name ) → integer
Converts the supplied encoding name into an integer representing the internal identifier used in some system catalog tables. Returns -1 if an unknown encoding name is provided.
pg_encoding_to_char ( encoding integer ) → name
Converts the integer used as the internal identifier of an encoding in some system catalog tables into a human-readable string. Returns an empty string if an invalid encoding number is provided.
pg_get_catalog_foreign_keys () → setof record ( fktable regclass , fkcols text[] , pktable regclass , pkcols text[] , is_array boolean , is_opt boolean )
Returns a set of records describing the foreign key relationships that exist within the PostgreSQL system catalogs. The fktable column contains the name of the referencing catalog, and the fkcols column contains the name(s) of the referencing column(s). Similarly, the pktable column contains the name of the referenced catalog, and the pkcols column contains the name(s) of the referenced column(s). If is_array is true, the last referencing column is an array, each of whose elements should match some entry in the referenced catalog. If is_opt is true, the referencing column(s) are allowed to contain zeroes instead of a valid reference.
pg_get_constraintdef ( constraint oid [ , pretty boolean ] ) → text
Reconstructs the creating command for a constraint. (This is a decompiled reconstruction, not the original text of the command.)
pg_get_expr ( expr pg_node_tree , relation oid [ , pretty boolean ] ) → text
Decompiles the internal form of an expression stored in the system catalogs, such as the default value for a column. If the expression might contain Vars, specify the OID of the relation they refer to as the second parameter; if no Vars are expected, passing zero is sufficient.
pg_get_functiondef ( func oid ) → text
Reconstructs the creating command for a function or procedure. (This is a decompiled reconstruction, not the original text of the command.) The result is a complete CREATE OR REPLACE FUNCTION or CREATE OR REPLACE PROCEDURE statement.
pg_get_function_arguments ( func oid ) → text
Reconstructs the argument list of a function or procedure, in the form it would need to appear in within CREATE FUNCTION (including default values).
pg_get_function_identity_arguments ( func oid ) → text
Reconstructs the argument list necessary to identify a function or procedure, in the form it would need to appear in within commands such as ALTER FUNCTION . This form omits default values.
pg_get_function_result ( func oid ) → text
Reconstructs the RETURNS clause of a function, in the form it would need to appear in within CREATE FUNCTION . Returns NULL for a procedure.
pg_get_indexdef ( index oid [ , column integer , pretty boolean ] ) → text
Reconstructs the creating command for an index. (This is a decompiled reconstruction, not the original text of the command.) If column is supplied and is not zero, only the definition of that column is reconstructed.
pg_get_keywords () → setof record ( word text , catcode «char» , barelabel boolean , catdesc text , baredesc text )
Returns a set of records describing the SQL keywords recognized by the server. The word column contains the keyword. The catcode column contains a category code: U for an unreserved keyword, C for a keyword that can be a column name, T for a keyword that can be a type or function name, or R for a fully reserved keyword. The barelabel column contains true if the keyword can be used as a “ bare ” column label in SELECT lists, or false if it can only be used after AS . The catdesc column contains a possibly-localized string describing the keyword’s category. The baredesc column contains a possibly-localized string describing the keyword’s column label status.
pg_get_ruledef ( rule oid [ , pretty boolean ] ) → text
Reconstructs the creating command for a rule. (This is a decompiled reconstruction, not the original text of the command.)
pg_get_serial_sequence ( table text , column text ) → text
Returns the name of the sequence associated with a column, or NULL if no sequence is associated with the column. If the column is an identity column, the associated sequence is the sequence internally created for that column. For columns created using one of the serial types ( serial , smallserial , bigserial ), it is the sequence created for that serial column definition. In the latter case, the association can be modified or removed with ALTER SEQUENCE OWNED BY . (This function probably should have been called pg_get_owned_sequence ; its current name reflects the fact that it has historically been used with serial-type columns.) The first parameter is a table name with optional schema, and the second parameter is a column name. Because the first parameter potentially contains both schema and table names, it is parsed per usual SQL rules, meaning it is lower-cased by default. The second parameter, being just a column name, is treated literally and so has its case preserved. The result is suitably formatted for passing to the sequence functions (see Section 9.17).
A typical use is in reading the current value of the sequence for an identity or serial column, for example:
pg_get_statisticsobjdef ( statobj oid ) → text
Reconstructs the creating command for an extended statistics object. (This is a decompiled reconstruction, not the original text of the command.)
pg_get_triggerdef ( trigger oid [ , pretty boolean ] ) → text
Reconstructs the creating command for a trigger. (This is a decompiled reconstruction, not the original text of the command.)
pg_get_userbyid ( role oid ) → name
Returns a role’s name given its OID.
pg_get_viewdef ( view oid [ , pretty boolean ] ) → text
Reconstructs the underlying SELECT command for a view or materialized view. (This is a decompiled reconstruction, not the original text of the command.)
pg_get_viewdef ( view oid , wrap_column integer ) → text
Reconstructs the underlying SELECT command for a view or materialized view. (This is a decompiled reconstruction, not the original text of the command.) In this form of the function, pretty-printing is always enabled, and long lines are wrapped to try to keep them shorter than the specified number of columns.
pg_get_viewdef ( view text [ , pretty boolean ] ) → text
Reconstructs the underlying SELECT command for a view or materialized view, working from a textual name for the view rather than its OID. (This is deprecated; use the OID variant instead.)
pg_index_column_has_property ( index regclass , column integer , property text ) → boolean
Tests whether an index column has the named property. Common index column properties are listed in Table 9.72. (Note that extension access methods can define additional property names for their indexes.) NULL is returned if the property name is not known or does not apply to the particular object, or if the OID or column number does not identify a valid object.
pg_index_has_property ( index regclass , property text ) → boolean
Tests whether an index has the named property. Common index properties are listed in Table 9.73. (Note that extension access methods can define additional property names for their indexes.) NULL is returned if the property name is not known or does not apply to the particular object, or if the OID does not identify a valid object.
pg_indexam_has_property ( am oid , property text ) → boolean
Tests whether an index access method has the named property. Access method properties are listed in Table 9.74. NULL is returned if the property name is not known or does not apply to the particular object, or if the OID does not identify a valid object.
pg_options_to_table ( options_array text[] ) → setof record ( option_name text , option_value text )
Returns the set of storage options represented by a value from pg_class . reloptions or pg_attribute . attoptions .
pg_settings_get_flags ( guc text ) → text[]
Returns an array of the flags associated with the given GUC, or NULL if it does not exist. The result is an empty array if the GUC exists but there are no flags to show. Only the most useful flags listed in Table 9.75 are exposed.
pg_tablespace_databases ( tablespace oid ) → setof oid
Returns the set of OIDs of databases that have objects stored in the specified tablespace. If this function returns any rows, the tablespace is not empty and cannot be dropped. To identify the specific objects populating the tablespace, you will need to connect to the database(s) identified by pg_tablespace_databases and query their pg_class catalogs.
pg_tablespace_location ( tablespace oid ) → text
Returns the file system path that this tablespace is located in.
pg_typeof ( «any» ) → regtype
Returns the OID of the data type of the value that is passed to it. This can be helpful for troubleshooting or dynamically constructing SQL queries. The function is declared as returning regtype , which is an OID alias type (see Section 8.19); this means that it is the same as an OID for comparison purposes but displays as a type name.
COLLATION FOR ( «any» ) → text
Returns the name of the collation of the value that is passed to it. The value is quoted and schema-qualified if necessary. If no collation was derived for the argument expression, then NULL is returned. If the argument is not of a collatable data type, then an error is raised.
to_regclass ( text ) → regclass
Translates a textual relation name to its OID. A similar result is obtained by casting the string to type regclass (see Section 8.19); however, this function will return NULL rather than throwing an error if the name is not found. Also unlike the cast, this does not accept a numeric OID as input.
to_regcollation ( text ) → regcollation
Translates a textual collation name to its OID. A similar result is obtained by casting the string to type regcollation (see Section 8.19); however, this function will return NULL rather than throwing an error if the name is not found. Also unlike the cast, this does not accept a numeric OID as input.
to_regnamespace ( text ) → regnamespace
Translates a textual schema name to its OID. A similar result is obtained by casting the string to type regnamespace (see Section 8.19); however, this function will return NULL rather than throwing an error if the name is not found. Also unlike the cast, this does not accept a numeric OID as input.
to_regoper ( text ) → regoper
Translates a textual operator name to its OID. A similar result is obtained by casting the string to type regoper (see Section 8.19); however, this function will return NULL rather than throwing an error if the name is not found or is ambiguous. Also unlike the cast, this does not accept a numeric OID as input.
to_regoperator ( text ) → regoperator
Translates a textual operator name (with parameter types) to its OID. A similar result is obtained by casting the string to type regoperator (see Section 8.19); however, this function will return NULL rather than throwing an error if the name is not found. Also unlike the cast, this does not accept a numeric OID as input.
to_regproc ( text ) → regproc
Translates a textual function or procedure name to its OID. A similar result is obtained by casting the string to type regproc (see Section 8.19); however, this function will return NULL rather than throwing an error if the name is not found or is ambiguous. Also unlike the cast, this does not accept a numeric OID as input.
to_regprocedure ( text ) → regprocedure
Translates a textual function or procedure name (with argument types) to its OID. A similar result is obtained by casting the string to type regprocedure (see Section 8.19); however, this function will return NULL rather than throwing an error if the name is not found. Also unlike the cast, this does not accept a numeric OID as input.
to_regrole ( text ) → regrole
Translates a textual role name to its OID. A similar result is obtained by casting the string to type regrole (see Section 8.19); however, this function will return NULL rather than throwing an error if the name is not found. Also unlike the cast, this does not accept a numeric OID as input.
to_regtype ( text ) → regtype
Translates a textual type name to its OID. A similar result is obtained by casting the string to type regtype (see Section 8.19); however, this function will return NULL rather than throwing an error if the name is not found. Also unlike the cast, this does not accept a numeric OID as input.
Most of the functions that reconstruct (decompile) database objects have an optional pretty flag, which if true causes the result to be “ pretty-printed ” . Pretty-printing suppresses unnecessary parentheses and adds whitespace for legibility. The pretty-printed format is more readable, but the default format is more likely to be interpreted the same way by future versions of PostgreSQL ; so avoid using pretty-printed output for dump purposes. Passing false for the pretty parameter yields the same result as omitting the parameter.
Table 9.72. Index Column Properties
| Name | Description |
|---|---|
| asc | Does the column sort in ascending order on a forward scan? |
| desc | Does the column sort in descending order on a forward scan? |
| nulls_first | Does the column sort with nulls first on a forward scan? |
| nulls_last | Does the column sort with nulls last on a forward scan? |
| orderable | Does the column possess any defined sort ordering? |
| distance_orderable | Can the column be scanned in order by a “ distance ” operator, for example ORDER BY col <-> constant ? |
| returnable | Can the column value be returned by an index-only scan? |
| search_array | Does the column natively support col = ANY(array) searches? |
| search_nulls | Does the column support IS NULL and IS NOT NULL searches? |
Table 9.73. Index Properties
| Name | Description |
|---|---|
| clusterable | Can the index be used in a CLUSTER command? |
| index_scan | Does the index support plain (non-bitmap) scans? |
| bitmap_scan | Does the index support bitmap scans? |
| backward_scan | Can the scan direction be changed in mid-scan (to support FETCH BACKWARD on a cursor without needing materialization)? |
Table 9.74. Index Access Method Properties
| Name | Description |
|---|---|
| can_order | Does the access method support ASC , DESC and related keywords in CREATE INDEX ? |
| can_unique | Does the access method support unique indexes? |
| can_multi_col | Does the access method support indexes with multiple columns? |
| can_exclude | Does the access method support exclusion constraints? |
| can_include | Does the access method support the INCLUDE clause of CREATE INDEX ? |
Table 9.75. GUC Flags
| Flag | Description |
|---|---|
| EXPLAIN | Parameters with this flag are included in EXPLAIN (SETTINGS) commands. |
| NO_SHOW_ALL | Parameters with this flag are excluded from SHOW ALL commands. |
| NO_RESET_ALL | Parameters with this flag are excluded from RESET ALL commands. |
| NOT_IN_SAMPLE | Parameters with this flag are not included in postgresql.conf by default. |
| RUNTIME_COMPUTED | Parameters with this flag are runtime-computed ones. |
Table 9.76 lists functions related to database object identification and addressing.
Table 9.76. Object Information and Addressing Functions
pg_describe_object ( classid oid , objid oid , objsubid integer ) → text
Returns a textual description of a database object identified by catalog OID, object OID, and sub-object ID (such as a column number within a table; the sub-object ID is zero when referring to a whole object). This description is intended to be human-readable, and might be translated, depending on server configuration. This is especially useful to determine the identity of an object referenced in the pg_depend catalog. This function returns NULL values for undefined objects.
pg_identify_object ( classid oid , objid oid , objsubid integer ) → record ( type text , schema text , name text , identity text )
Returns a row containing enough information to uniquely identify the database object specified by catalog OID, object OID and sub-object ID. This information is intended to be machine-readable, and is never translated. type identifies the type of database object; schema is the schema name that the object belongs in, or NULL for object types that do not belong to schemas; name is the name of the object, quoted if necessary, if the name (along with schema name, if pertinent) is sufficient to uniquely identify the object, otherwise NULL ; identity is the complete object identity, with the precise format depending on object type, and each name within the format being schema-qualified and quoted as necessary. Undefined objects are identified with NULL values.
pg_identify_object_as_address ( classid oid , objid oid , objsubid integer ) → record ( type text , object_names text[] , object_args text[] )
Returns a row containing enough information to uniquely identify the database object specified by catalog OID, object OID and sub-object ID. The returned information is independent of the current server, that is, it could be used to identify an identically named object in another server. type identifies the type of database object; object_names and object_args are text arrays that together form a reference to the object. These three values can be passed to pg_get_object_address to obtain the internal address of the object.
pg_get_object_address ( type text , object_names text[] , object_args text[] ) → record ( classid oid , objid oid , objsubid integer )
Returns a row containing enough information to uniquely identify the database object specified by a type code and object name and argument arrays. The returned values are the ones that would be used in system catalogs such as pg_depend ; they can be passed to other system functions such as pg_describe_object or pg_identify_object . classid is the OID of the system catalog containing the object; objid is the OID of the object itself, and objsubid is the sub-object ID, or zero if none. This function is the inverse of pg_identify_object_as_address . Undefined objects are identified with NULL values.
The functions shown in Table 9.77 extract comments previously stored with the COMMENT command. A null value is returned if no comment could be found for the specified parameters.
Table 9.77. Comment Information Functions
col_description ( table oid , column integer ) → text
Returns the comment for a table column, which is specified by the OID of its table and its column number. ( obj_description cannot be used for table columns, since columns do not have OIDs of their own.)
obj_description ( object oid , catalog name ) → text
Returns the comment for a database object specified by its OID and the name of the containing system catalog. For example, obj_description(123456, ‘pg_class’) would retrieve the comment for the table with OID 123456.
obj_description ( object oid ) → text
Returns the comment for a database object specified by its OID alone. This is deprecated since there is no guarantee that OIDs are unique across different system catalogs; therefore, the wrong comment might be returned.
shobj_description ( object oid , catalog name ) → text
Returns the comment for a shared database object specified by its OID and the name of the containing system catalog. This is just like obj_description except that it is used for retrieving comments on shared objects (that is, databases, roles, and tablespaces). Some system catalogs are global to all databases within each cluster, and the descriptions for objects in them are stored globally as well.
The functions shown in Table 9.78 provide server transaction information in an exportable form. The main use of these functions is to determine which transactions were committed between two snapshots.
Table 9.78. Transaction ID and Snapshot Information Functions
Returns the current transaction’s ID. It will assign a new one if the current transaction does not have one already (because it has not performed any database updates).
Returns the current transaction’s ID, or NULL if no ID is assigned yet. (It’s best to use this variant if the transaction might otherwise be read-only, to avoid unnecessary consumption of an XID.)
pg_xact_status ( xid8 ) → text
Reports the commit status of a recent transaction. The result is one of in progress , committed , or aborted , provided that the transaction is recent enough that the system retains the commit status of that transaction. If it is old enough that no references to the transaction survive in the system and the commit status information has been discarded, the result is NULL . Applications might use this function, for example, to determine whether their transaction committed or aborted after the application and database server become disconnected while a COMMIT is in progress. Note that prepared transactions are reported as in progress ; applications must check pg_prepared_xacts if they need to determine whether a transaction ID belongs to a prepared transaction.
Returns a current snapshot, a data structure showing which transaction IDs are now in-progress.
pg_snapshot_xip ( pg_snapshot ) → setof xid8
Returns the set of in-progress transaction IDs contained in a snapshot.
pg_snapshot_xmax ( pg_snapshot ) → xid8
Returns the xmax of a snapshot.
pg_snapshot_xmin ( pg_snapshot ) → xid8
Returns the xmin of a snapshot.
pg_visible_in_snapshot ( xid8 , pg_snapshot ) → boolean
Is the given transaction ID visible according to this snapshot (that is, was it completed before the snapshot was taken)? Note that this function will not give the correct answer for a subtransaction ID.
The internal transaction ID type xid is 32 bits wide and wraps around every 4 billion transactions. However, the functions shown in Table 9.78 use a 64-bit type xid8 that does not wrap around during the life of an installation, and can be converted to xid by casting if required. The data type pg_snapshot stores information about transaction ID visibility at a particular moment in time. Its components are described in Table 9.79. pg_snapshot ‘s textual representation is xmin : xmax : xip_list . For example 10:20:10,14,15 means xmin=10, xmax=20, xip_list=10, 14, 15 .
Table 9.79. Snapshot Components
| Name | Description |
|---|---|
| xmin | Lowest transaction ID that was still active. All transaction IDs less than xmin are either committed and visible, or rolled back and dead. |
| xmax | One past the highest completed transaction ID. All transaction IDs greater than or equal to xmax had not yet completed as of the time of the snapshot, and thus are invisible. |
| xip_list | Transactions in progress at the time of the snapshot. A transaction ID that is xmin <= X < xmax and not in this list was already completed at the time of the snapshot, and thus is either visible or dead according to its commit status. This list does not include the transaction IDs of subtransactions. |
In releases of PostgreSQL before 13 there was no xid8 type, so variants of these functions were provided that used bigint to represent a 64-bit XID, with a correspondingly distinct snapshot data type txid_snapshot . These older functions have txid in their names. They are still supported for backward compatibility, but may be removed from a future release. See Table 9.80.
Table 9.80. Deprecated Transaction ID and Snapshot Information Functions
click fraud protection
Ранее его основная версия была представлена в виде десятичного числа, например, 9,6 или 9,0. После PostgreSQL 10 центральная часть версии увеличивается на один номер для основных версий выпуска, например, 10, 11, 12, и т. д.
Минорная версия PostgreSQL
Последний номер части версии показывает второстепенный номер выпуска. Например, 10.4 или 10.6 — это младшие версии PostgreSQL версии 10. Раньше для установки была доступна версия 13.3 PostgreSQL. В этом руководстве мы рассмотрим различные методы проверки версии PostgreSQL.
Как проверить версию PostgreSQL
Проверить версию PostgreSQL можно несколькими способами. Здесь мы разберемся во всех методах и посмотрим, как можно проверить версию PostgreSQL в вашей системе.
Проверьте версию PostgreSQL с помощью командной строки
Вы можете проверить текущую версию PostgreSQL, работающую в вашей системе, с помощью командной строки. Вы можете сделать это, войдя в терминал и выполнив следующую команду:
Вы можете запустить любую из предыдущих команд и проверить версию PostgreSQL. Обе команды предоставят вам один и тот же результат.
Вы получаете сообщение об ошибке «Postgres: команда не найдена», если двоичный файл Postgres отсутствует в пути к файловой системе. Давайте устраним эту проблему, выполнив поиск в двоичном каталоге PostgreSQL. Выполните следующую команду в окне терминала:
С помощью этой команды вы можете увидеть полный путь к бинарной папке PostgreSQL в вашем терминале. Введите полный путь, чтобы узнать, какая у вас версия PostgreSQL:
/usr/lib/postgresql/ 12 /bin/постгрес -V
/usr/lib/postgresql/ 12 /bin/postgres —версия
Обе эти команды предоставят вам один и тот же результат.
Проверьте версию PostgreSQL с помощью SQL Shell
Вы можете получить версию PostgreSQL через приглашение PostgreSQL. Версии PostgreSQL отображаются на экране после входа в систему после входа на сервер PostgreSQL через терминал.
Сервер должен войти в приглашение SQL и получить результат, выполнив команду SQL.
sudo -u postres psql
Через параметры
Вы можете проверить версию PostgreSQL по предустановленному параметру. Автоматическая проверка версии также возможна с использованием следующего метода:
Через функцию version()
Выполняя version(), вы также можете определить версию PostgreSQL. Вы также можете проверить версию PostgreSQL в скрипте автоматизации.
Проверьте версию PostgreSQL Версия клиента PSQL
Помимо того, что это клиент PostgreSQL, psql также является утилитой командной строки на базе терминала. Psql предоставляет пользователям доступ к базам данных PostgreSQL. Информацию о версии клиентской утилиты psql можно найти с помощью следующей команды:
Предыдущие команды предоставят вам тот же вывод, который может использовать кто угодно.
Версия Postgres в pgAdmin4
Веб-интерфейс pgAdmin4 — отличный способ управления серверами PostgreSQL. Веб-интерфейс показывает версию Postgres для пользователей pgAdmin4. Чтобы узнать версию PostgreSQL, выполните следующие действия:
- Войдите в pgAdmin4.
- Выберите свой сервер Postgres, развернув серверы на левой боковой панели.
- Теперь перейдите на вкладку свойств.
- Последний шаг — проверить версию PostgreSQL в общем разделе.
Вывод
В этом руководстве мы обсудили несколько методов проверки версии PostgreSQL и увидели, насколько легко проверить каждую версию. Мы надеемся, что благодаря этой статье вы поняли все методы и научились проверять версию PostgreSQL каждым методом. Прочтите другие статьи Linux Hint, чтобы узнать больше советов и руководств.