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Environment VariablesManual ChaptersPG1817.5.2. Environment Variables If you installed into /usr/local/pgsql or some other location that is not searched for programs by default, you should add /usr/local/pgsql/bin (or whatever you…Environment Variables Environment VariablesManual ChaptersPG1832.15. Environment Variables The following environment variables can be used to select default connection parameter values, which will be used by PQconnectdb, PQsetdbLogin and PQsetdb if no …Environment Variables Environment VariablesManual ChaptersPG1844.11. Environment Variables Some of the environment variables that are accepted by the Python interpreter can also be used to affect PL/Python behavior. They would need to be set in the env…Environment Variables Environment VariablesManual ChaptersPG1831.4.1. Environment Variables Data directories are named according to the test filename, and will be retained if a test fails. If the environment variable PG_TEST_NOCLEAN is set, data direct…Environment Variables errno Values of pgtypeslibManual ChaptersPG1834.6.7. errno Values of pgtypeslib PGTYPES_NUM_BAD_NUMERIC # An argument should contain a numeric variable (or point to a numeric variable) but in fact its in-memory representation was inval…errno Values of pgtypeslib Error and Notice Message FieldsManual ChaptersPG1854.8. Error and Notice Message Fields This section describes the fields that can appear in ErrorResponse and NoticeResponse messages. Each field type has a single-byte identification token. …Error and Notice Message Fields Error HandlingManual ChaptersPG1834.8. Error Handling This section describes how you can handle exceptional conditions and warnings in an embedded SQL program. There are two nonexclusive facilities for this. Callbacks can b…Error Handling Error HandlingManual ChaptersPG1832.5.1.3. Error Handling From the client's perspective, after PQresultStatus returns PGRES_FATAL_ERROR, the pipeline is flagged as aborted. PQresultStatus will report a PGRES_PIPELINE_ABORTE…Error Handling Error HandlingManual ChaptersPG1819.14. Error Handling exit_on_error (boolean) # If on, any error will terminate the current session. By default, this is set to off, so that only FATAL errors will terminate the session. res…Error Handling Error Handling in PL/TclManual ChaptersPG1842.8. Error Handling in PL/Tcl Tcl code within or called from a PL/Tcl function can raise an error, either by executing some invalid operation or by generating an error using the Tcl error c…Error Handling in PL/Tcl Error Message DifferencesManual ChaptersPG1831.2.1. Error Message Differences Some of the regression tests involve intentional invalid input values. Error messages can come from either the PostgreSQL code or from the host platform sys…Error Message Differences Error Message Style GuideManual ChaptersPG1855.3. Error Message Style Guide This style guide is offered in the hope of maintaining a consistent, user-friendly style throughout all the messages generated by PostgreSQL. What Goes Where …Error Message Style Guide Error Reporting and LoggingManual ChaptersPG1819.8. Error Reporting and LoggingError Reporting and Logging Errors and MessagesManual ChaptersPG1841.9. Errors and MessagesErrors and Messages Escaping Strings for Inclusion in SQL CommandsManual ChaptersPG1832.3.4. Escaping Strings for Inclusion in SQL Commands PQescapeLiteral char *PQescapeLiteral(PGconn *conn, const char *str, size_t length); PQescapeLiteral escapes a string for use within an…Escaping Strings for Inclusion in SQL Commands Event Callback ProcedureManual ChaptersPG1832.14.2. Event Callback Procedure PGEventProc # PGEventProc is a typedef for a pointer to an event procedure, that is, the user callback function that receives events from libpq. The signatu…Event Callback Procedure Event ExampleManual ChaptersPG1832.14.4. Event Example Here is a skeleton example of managing private data associated with libpq connections and results. /* required header for libpq events (note: includes libpq-fe.h) */ #…Event Example Event Support FunctionsManual ChaptersPG1832.14.3. Event Support Functions PQregisterEventProc # Registers an event callback procedure with libpq. int PQregisterEventProc(PGconn *conn, PGEventProc proc, const char *name, void *passT…Event Support Functions Event SystemManual ChaptersPG1832.14. Event System libpq's event system is designed to notify registered event handlers about interesting libpq events, such as the creation or destruction of PGconn and PGresult objects. A…Event System Event Trigger FunctionsManual ChaptersPG189.30. Event Trigger Functions PostgreSQL provides these helper functions to retrieve information from event triggers. For more information about event triggers, see Chapter 38.Event Trigger Functions Event Trigger Functions in PL/TclManual ChaptersPG1842.7. Event Trigger Functions in PL/Tcl Event trigger functions can be written in PL/Tcl. PostgreSQL requires that a function that is to be called as an event trigger must be declared as a f…Event Trigger Functions in PL/Tcl Event TriggersManual ChaptersPG18Chapter 38. Event Triggers To supplement the trigger mechanism discussed in Chapter 37, PostgreSQL also provides event triggers. Unlike regular triggers, which are attached to a single table…Event Triggers Event Triggers in Aborted TransactionsManual ChaptersPG1838.1.6. Event Triggers in Aborted Transactions Event triggers (like other functions) cannot be executed in an aborted transaction. Thus, if a DDL command fails with an error, any associated …Event Triggers in Aborted Transactions Event TypesManual ChaptersPG1832.14.1. Event Types The enum PGEventId names the types of events handled by the event system. All its values have names beginning with PGEVT. For each event type, there is a corresponding e…Event Types Examining Index UsageManual ChaptersPG1811.12. Examining Index Usage Although indexes in PostgreSQL do not need maintenance or tuning, it is still important to check which indexes are actually used by the real-life query workload.…Examining Index Usage ExampleManual ChaptersPG18Example To reproduce the build configuration of the current PostgreSQL installation, run the following command: eval ./configure `pg_config --configure` The output of pg_config --configure c…Example ExampleManual ChaptersPG18F.3.2. Example postgres=# LOAD 'auto_explain'; postgres=# SET auto_explain.log_min_duration = 0; postgres=# SET auto_explain.log_analyze = true; postgres=# SELECT count(*) FROM pg_class, pg_…Example ExampleManual ChaptersPG185.12.2.1. Example Suppose we are constructing a database for a large ice cream company. The company measures peak temperatures every day as well as ice cream sales in each region. Conceptual…Example ExampleManual ChaptersPG185.12.3.1. Example This example builds a partitioning structure equivalent to the declarative partitioning example above. Use the following steps: Create the “root” table, from which all of t…Example ExampleManual ChaptersPG18F.19.3. Example -- a message can be in one or more “sections” CREATE TABLE message (mid INT PRIMARY KEY, sections INT[], ...); -- create specialized index with signature length of 32 bytes C…Example ExampleManual ChaptersPG18F.22.4. Example This example uses the following data (also available in file contrib/ltree/ltreetest.sql in the source distribution): CREATE TABLE test (path ltree); INSERT INTO test VALUES …Example Example ProgramManual ChaptersPG1833.5. Example Program Example 33.1 is a sample program which shows how the large object interface in libpq can be used. Parts of the program are commented out but are left in the source for …Example Program Example ProgramsManual ChaptersPG1832.23. Example Programs These examples and others can be found in the directory src/test/examples in the source code distribution. Example 32.1. libpq Example Program 1 /* * src/test/example…Example Programs Example UsageManual ChaptersPG18F.7.1. Example Usage CREATE TABLE test (a int4); -- create index CREATE INDEX testidx ON test USING GIN (a); -- query SELECT * FROM test WHERE a < 10;Example Usage Example UsageManual ChaptersPG18F.8.1. Example Usage Simple example using btree_gist instead of btree: CREATE TABLE test (a int4); -- create index CREATE INDEX testidx ON test USING GIST (a); -- query SELECT * FROM test WH…Example Usage ExamplesManual ChaptersPG18Examples To cluster the database test: $ clusterdb test To cluster a single table foo in a database named xyzzy: $ clusterdb --table=foo xyzzyExamples ExamplesManual ChaptersPG18Examples To create the database demo using the default database server: $ createdb demo To create the database demo using the server on host eden, port 5000, using the template0 template dat…Examples ExamplesManual ChaptersPG18Examples To create a user joe on the default database server: $ createuser joe To create a user joe on the default database server with prompting for some additional attributes: $ createuser…Examples ExamplesManual ChaptersPG18Examples To destroy the database demo on the default database server: $ dropdb demo To destroy the database demo using the server on host eden, port 5000, with verification and a peek at the…Examples ExamplesManual ChaptersPG18Examples To remove user joe from the default database server: $ dropuser joe To remove user joe using the server on host eden, port 5000, with verification and a peek at the underlying comma…Examples