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Remote Execution OptionsManual ChaptersPG18F.38.1.4. Remote Execution Options By default, only WHERE clauses using built-in operators and functions will be considered for execution on the remote server. Clauses involving non-built-in…Remote Execution Options Remote Query Execution EnvironmentManual ChaptersPG18F.38.6. Remote Query Execution Environment In the remote sessions opened by postgres_fdw, the search_path parameter is set to just pg_catalog, so that only built-in objects are visible witho…Remote Query Execution Environment Remote Query OptimizationManual ChaptersPG18F.38.5. Remote Query Optimization postgres_fdw attempts to optimize remote queries to reduce the amount of data transferred from foreign servers. This is done by sending query WHERE clauses …Remote Query Optimization Remove Foreign Key ConstraintsManual ChaptersPG1814.4.4. Remove Foreign Key Constraints Just as with indexes, a foreign key constraint can be checked “in bulk” more efficiently than row-by-row. So it might be useful to drop foreign key con…Remove Foreign Key Constraints Remove IndexesManual ChaptersPG1814.4.3. Remove Indexes If you are loading a freshly created table, the fastest method is to create the table, bulk load the table's data using COPY, then create any indexes needed for the ta…Remove Indexes Removing a ColumnManual ChaptersPG185.7.2. Removing a Column To remove a column, use a command like: ALTER TABLE products DROP COLUMN description; Whatever data was in the column disappears. Table constraints involving the col…Removing a Column Removing a ConstraintManual ChaptersPG185.7.4. Removing a Constraint To remove a constraint you need to know its name. If you gave it a name then that's easy. Otherwise the system assigned a generated name, which you need to find …Removing a Constraint Removing a Large ObjectManual ChaptersPG1833.3.11. Removing a Large Object To remove a large object from the database, call int lo_unlink(PGconn *conn, Oid lobjId); The lobjId argument specifies the OID of the large object to remove…Removing a Large Object Renaming a ColumnManual ChaptersPG185.7.7. Renaming a Column To rename a column: ALTER TABLE products RENAME COLUMN product_no TO product_number;Renaming a Column Renaming a TableManual ChaptersPG185.7.8. Renaming a Table To rename a table: ALTER TABLE products RENAME TO items;Renaming a Table Repairing CorruptionManual ChaptersPG18F.1.4. Repairing Corruption No error concerning corruption raised by amcheck should ever be a false positive. amcheck raises errors in the event of conditions that, by definition, should nev…Repairing Corruption Repeatable Read Isolation LevelManual ChaptersPG1813.2.2. Repeatable Read Isolation Level The Repeatable Read isolation level only sees data committed before the transaction began; it never sees either uncommitted data or changes committed …Repeatable Read Isolation Level Replica IdentityManual ChaptersPG1829.1.1. Replica Identity A published table must have a replica identity configured in order to be able to replicate UPDATE and DELETE operations, so that appropriate rows to update or delete…Replica Identity ReplicationManual ChaptersPG1819.6. Replication These settings control the behavior of the built-in streaming replication feature (see Section 26.2.5), and the built-in logical replication feature (see Chapter 29). For s…Replication Replication Management FunctionsManual ChaptersPG189.28.6. Replication Management Functions The functions shown in Table 9.101 are for controlling and interacting with replication features. See Section 26.2.5, Section 26.2.6, and Chapter 48 …Replication Management Functions Replication Progress TrackingManual ChaptersPG18Chapter 48. Replication Progress Tracking Replication origins are intended to make it easier to implement logical replication solutions on top of logical decoding. They provide a solution to…Replication Progress Tracking Replication Slot ManagementManual ChaptersPG1829.2.1. Replication Slot Management As mentioned earlier, each (active) subscription receives changes from a replication slot on the remote (publishing) side. Additional table synchronizatio…Replication Slot Management Replication Slot SynchronizationManual ChaptersPG1847.2.3. Replication Slot Synchronization The logical replication slots on the primary can be synchronized to the hot standby by using the failover parameter of pg_create_logical_replication_…Replication Slot Synchronization Replication SlotsManual ChaptersPG1847.2.2. Replication Slots In the context of logical replication, a slot represents a stream of changes that can be replayed to a client in the order they were made on the origin server. Each…Replication Slots Replication SlotsManual ChaptersPG1826.2.6. Replication Slots Replication slots provide an automated way to ensure that the primary server does not remove WAL segments until they have been received by all standbys, and that th…Replication Slots Reporting Errors and MessagesManual ChaptersPG1841.9.1. Reporting Errors and Messages Use the RAISE statement to report messages and raise errors. RAISE [ level ] 'format' [, expression [, ... ]] [ USING option { = | := } expression [, ..…Reporting Errors and Messages Reporting Errors Within the ServerManual ChaptersPG1855.2. Reporting Errors Within the Server Error, warning, and log messages generated within the server code should be created using ereport, or its older cousin elog. The use of this function…Reporting Errors Within the Server Requesting LWLocks After StartupManual ChaptersPG1836.10.12.2. Requesting LWLocks After Startup There is another, more flexible method of obtaining LWLocks that can be done after server startup and outside a shmem_request_hook. To do so, fir…Requesting LWLocks After Startup Requesting LWLocks at StartupManual ChaptersPG1836.10.12.1. Requesting LWLocks at Startup Add-ins can reserve LWLocks on server startup. As with shared memory reserved at server startup, the add-in's shared library must be preloaded by sp…Requesting LWLocks at Startup Requesting Shared Memory After StartupManual ChaptersPG1836.10.11.2. Requesting Shared Memory After Startup There is another, more flexible method of reserving shared memory that can be done after server startup and outside a shmem_request_hook. T…Requesting Shared Memory After Startup Requesting Shared Memory at StartupManual ChaptersPG1836.10.11.1. Requesting Shared Memory at Startup Add-ins can reserve shared memory on server startup. To do so, the add-in's shared library must be preloaded by specifying it in shared_preloa…Requesting Shared Memory at Startup Required ToolsManual ChaptersPG1817.7.4.1. Required Tools You can build with either GCC or Sun's compiler suite. For better code optimization, Sun's compiler is strongly recommended on the SPARC architecture. If you are usi…Required Tools RequirementsManual ChaptersPG1817.1. Requirements In general, a modern Unix-compatible platform should be able to run PostgreSQL. The platforms that had received specific testing at the time of release are described in Se…Requirements RequirementsManual ChaptersPG1817.7.5.1. Requirements The following additional products are required to build PostgreSQL on Windows. Strawberry Perl Strawberry Perl is required to run the build generation scripts. MinGW o…Requirements RequirementsManual ChaptersPG1856.1.1. Requirements We won't judge your language skills — this section is about software tools. Theoretically, you only need a text editor. But this is only in the unlikely event that you d…Requirements RESETManual ChaptersPG18RESET RESET — restore the value of a run-time parameter to the default value Synopsis RESET configuration_parameter RESET ALLRESET Resource ConsumptionManual ChaptersPG1819.4. Resource ConsumptionResource Consumption Resource LimitsManual ChaptersPG1818.4.3. Resource Limits Unix-like operating systems enforce various kinds of resource limits that might interfere with the operation of your PostgreSQL server. Of particular importance are l…Resource Limits Restarting the ServerManual ChaptersPG18Restarting the Server Restarting the server is almost equivalent to stopping the server and starting it again, except that by default, pg_ctl saves and reuses the command line options that w…Restarting the Server Restoring the DumpManual ChaptersPG1825.1.1. Restoring the Dump Text files created by pg_dump are intended to be read by the psql program using its default settings. The general command form to restore a text dump is psql -X db…Restoring the Dump RESTRICTManual ChaptersPG1836.15.3. RESTRICT The RESTRICT clause, if provided, names a restriction selectivity estimation function for the operator. (Note that this is a function name, not an operator name.) RESTRICT …RESTRICT Restriction of XPath to 1.0Manual ChaptersPG18D.3.1.2. Restriction of XPath to 1.0 For developers familiar with XQuery and XPath 2.0 or later, XPath 1.0 presents a number of differences to contend with: The fundamental type of an XQuery…Restriction of XPath to 1.0 Restriction of XQuery to XPathManual ChaptersPG18D.3.1.1. Restriction of XQuery to XPath Features of XQuery beyond those of XPath include: XQuery expressions can construct and return new XML nodes, in addition to all possible XPath values.…Restriction of XQuery to XPath RestrictionsManual ChaptersPG1829.8. Restrictions Logical replication currently has the following restrictions or missing functionality. These might be addressed in future releases. The database schema and DDL commands ar…Restrictions Retrieving a Result Set Using an SQLDAManual ChaptersPG1834.7.2.2. Retrieving a Result Set Using an SQLDA The general steps to retrieve a query result set through an SQLDA are: Declare an sqlda_t structure to receive the result set. Execute FETCH/…Retrieving a Result Set Using an SQLDA