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DescriptionManual ChaptersPG18Description pg_resetwal clears the write-ahead log (WAL) and optionally resets some other control information stored in the pg_control file. This function is sometimes needed if these files …Description DescriptionManual ChaptersPG18Description pg_restore is a utility for restoring a PostgreSQL database from an archive created by pg_dump in one of the non-plain-text formats. It will issue the commands necessary to recon…Description DescriptionManual ChaptersPG18Description pg_rewind is a tool for synchronizing a PostgreSQL cluster with another copy of the same cluster, after the clusters' timelines have diverged. A typical scenario is to bring an o…Description DescriptionManual ChaptersPG18Description pg_verifybackup is used to check the integrity of a database cluster backup taken using pg_basebackup against a backup_manifest generated by the server at the time of the backup.…Description DescriptionManual ChaptersPG18Description pg_walsummary is used to print the contents of WAL summary files. These binary files are found in the pg_wal/summaries subdirectory of the data directory, and can be converted to…Description DescriptionManual ChaptersPG18Description postgres is the PostgreSQL database server. In order for a client application to access a database it connects (over a network or locally) to a running postgres instance. The pos…Description DescriptionManual ChaptersPG18Description psql is a terminal-based front-end to PostgreSQL. It enables you to type in queries interactively, issue them to PostgreSQL, and see the query results. Alternatively, input can b…Description DescriptionManual ChaptersPG18Description reindexdb is a utility for rebuilding indexes in a PostgreSQL database. reindexdb is a wrapper around the SQL command REINDEX. There is no effective difference between reindexing…Description DescriptionManual ChaptersPG18Description vacuumdb is a utility for cleaning a PostgreSQL database. vacuumdb will also generate internal statistics used by the PostgreSQL query optimizer. vacuumdb is a wrapper around the…Description DescriptionManual ChaptersPG18Description dblink_build_sql_delete can be useful in doing selective replication of a local table to a remote database. It builds an SQL DELETE command that will delete the row with the give…Description DescriptionManual ChaptersPG18Description dblink_build_sql_insert can be useful in doing selective replication of a local table to a remote database. It selects a row from the local table based on primary key, and then b…Description DescriptionManual ChaptersPG18Description dblink_build_sql_update can be useful in doing selective replication of a local table to a remote database. It selects a row from the local table based on primary key, and then b…Description DescriptionManual ChaptersPG18Description dblink_cancel_query attempts to cancel any query that is in progress on the named connection. Note that this is not certain to succeed (since, for example, the remote query might…Description DescriptionManual ChaptersPG18Description dblink_close closes a cursor previously opened with dblink_open.Description DescriptionManual ChaptersPG18Description dblink_connect_u() is identical to dblink_connect(), except that it will allow non-superusers to connect using any authentication method. If the remote server selects an authenti…Description DescriptionManual ChaptersPG18Description dblink_connect() establishes a connection to a remote PostgreSQL database. The server and database to be contacted are identified through a standard libpq connection string. Opti…Description DescriptionManual ChaptersPG18Description dblink_disconnect() closes a connection previously opened by dblink_connect(). The form with no arguments closes an unnamed connection.Description DescriptionManual ChaptersPG18Description dblink_error_message fetches the most recent remote error message for a given connection.Description DescriptionManual ChaptersPG18Description dblink_exec executes a command (that is, any SQL statement that doesn't return rows) in a remote database. When two text arguments are given, the first one is first looked up as …Description DescriptionManual ChaptersPG18Description dblink_fetch fetches rows from a cursor previously established by dblink_open.Description DescriptionManual ChaptersPG18Description dblink executes a query (usually a SELECT, but it can be any SQL statement that returns rows) in a remote database. When two text arguments are given, the first one is first look…Description DescriptionManual ChaptersPG18Description dblink_get_connections returns an array of the names of all open named dblink connections.Description DescriptionManual ChaptersPG18Description dblink_get_notify retrieves notifications on either the unnamed connection, or on a named connection if specified. To receive notifications via dblink, LISTEN must first be issue…Description DescriptionManual ChaptersPG18Description dblink_get_pkey provides information about the primary key of a relation in the local database. This is sometimes useful in generating queries to be sent to remote databases.Description DescriptionManual ChaptersPG18Description dblink_get_result collects the results of an asynchronous query previously sent with dblink_send_query. If the query is not already completed, dblink_get_result will wait until i…Description DescriptionManual ChaptersPG18Description dblink_is_busy tests whether an async query is in progress.Description DescriptionManual ChaptersPG18Description dblink_open() opens a cursor in a remote database. The cursor can subsequently be manipulated with dblink_fetch() and dblink_close().Description DescriptionManual ChaptersPG18Description dblink_send_query sends a query to be executed asynchronously, that is, without immediately waiting for the result. There must not be an async query already in progress on the co…Description DescriptionManual ChaptersPG18Description ALLOCATE DESCRIPTOR allocates a new named SQL descriptor area, which can be used to exchange data between the PostgreSQL server and the host program. Descriptor areas should be f…Description DescriptionManual ChaptersPG18Description The CONNECT command establishes a connection between the client and the PostgreSQL server.Description DescriptionManual ChaptersPG18Description DEALLOCATE DESCRIPTOR deallocates a named SQL descriptor area.Description DescriptionManual ChaptersPG18Description DECLARE STATEMENT declares an SQL statement identifier. SQL statement identifier can be associated with the connection. When the identifier is used by dynamic SQL statements, the…Description DescriptionManual ChaptersPG18Description DECLARE declares a cursor for iterating over the result set of a prepared statement. This command has slightly different semantics from the direct SQL command DECLARE: Whereas th…Description DescriptionManual ChaptersPG18Description DESCRIBE retrieves metadata information about the result columns contained in a prepared statement, without actually fetching a row.Description DescriptionManual ChaptersPG18Description DISCONNECT closes a connection (or all connections) to the database.Description DescriptionManual ChaptersPG18Description EXECUTE IMMEDIATE immediately prepares and executes a dynamically specified SQL statement, without retrieving result rows.Description DescriptionManual ChaptersPG18Description GET DESCRIPTOR retrieves information about a query result set from an SQL descriptor area and stores it into host variables. A descriptor area is typically populated using FETCH …Description DescriptionManual ChaptersPG18Description OPEN opens a cursor and optionally binds actual values to the placeholders in the cursor's declaration. The cursor must previously have been declared with the DECLARE command. Th…Description DescriptionManual ChaptersPG18Description PREPARE prepares a statement dynamically specified as a string for execution. This is different from the direct SQL statement PREPARE, which can also be used in embedded programs…Description DescriptionManual ChaptersPG18Description SET AUTOCOMMIT sets the autocommit behavior of the current database session. By default, embedded SQL programs are not in autocommit mode, so COMMIT needs to be issued explicitly…Description