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ON CONFLICT ClauseManual ChaptersPG18ON CONFLICT Clause The optional ON CONFLICT clause specifies an alternative action to raising a unique violation or exclusion constraint violation error. For each individual row proposed for…ON CONFLICT Clause ONLY and InheritanceManual ChaptersPG18ONLY and Inheritance The SQL standard requires parentheses around the table name when writing ONLY, for example SELECT * FROM ONLY (tab1), ONLY (tab2) WHERE .... PostgreSQL considers these p…ONLY and Inheritance Only BY VALUE Passing Mechanism Is SupportedManual ChaptersPG18D.3.2.1. Only BY VALUE Passing Mechanism Is Supported The SQL standard defines two passing mechanisms that apply when passing an XML argument from SQL to an XML function or receiving a resul…Only BY VALUE Passing Mechanism Is Supported OPENManual ChaptersPG18OPEN OPEN — open a dynamic cursor Synopsis OPEN cursor_name OPEN cursor_name USING value [, ... ] OPEN cursor_name USING SQL DESCRIPTOR descriptor_nameOPEN OPEN FOR EXECUTEManual ChaptersPG1841.7.2.2. OPEN FOR EXECUTE OPEN unbound_cursorvar [ [ NO ] SCROLL ] FOR EXECUTE query_string [ USING expression [, ... ] ]; The cursor variable is opened and given the specified query to exe…OPEN FOR EXECUTE OPEN FOR queryManual ChaptersPG1841.7.2.1. OPEN FOR query OPEN unbound_cursorvar [ [ NO ] SCROLL ] FOR query; The cursor variable is opened and given the specified query to execute. The cursor cannot be open already, and it…OPEN FOR query Opening a Bound CursorManual ChaptersPG1841.7.2.3. Opening a Bound Cursor OPEN bound_cursorvar [ ( [ argument_name { := | => } ] argument_value [, ...] ) ]; This form of OPEN is used to open a cursor variable whose query was bound …Opening a Bound Cursor Opening an Existing Large ObjectManual ChaptersPG1833.3.4. Opening an Existing Large Object To open an existing large object for reading or writing, call int lo_open(PGconn *conn, Oid lobjId, int mode); The lobjId argument specifies the OID …Opening an Existing Large Object Opening CursorsManual ChaptersPG1841.7.2. Opening Cursors Before a cursor can be used to retrieve rows, it must be opened. (This is the equivalent action to the SQL command DECLARE CURSOR.) PL/pgSQL has three forms of the OP…Opening Cursors OpenSSL ConfigurationManual ChaptersPG1818.9.2. OpenSSL Configuration PostgreSQL reads the system-wide OpenSSL configuration file. By default, this file is named openssl.cnf and is located in the directory reported by openssl vers…OpenSSL Configuration OpenSSL Support FunctionsManual ChaptersPG18F.26.6. OpenSSL Support Functions fips_mode() returns boolean Returns true if OpenSSL is running with FIPS mode enabled, otherwise false.OpenSSL Support Functions Operator Class InterfaceManual ChaptersPG18F.6.3. Operator Class Interface An operator class for bloom indexes requires only a hash function for the indexed data type and an equality operator for searching. This example shows the ope…Operator Class Interface Operator Class ParametersManual ChaptersPG1865.5.2.1. Operator Class Parameters Some of the built-in operator classes allow specifying parameters affecting behavior of the operator class. Each operator class has its own set of allowed…Operator Class Parameters Operator Classes and Operator FamiliesManual ChaptersPG1811.10. Operator Classes and Operator Families An index definition can specify an operator class for each column of an index. CREATE INDEX name ON table (column opclass [ ( opclass_options ) …Operator Classes and Operator Families Operator Classes and Operator FamiliesManual ChaptersPG1836.16.5. Operator Classes and Operator Families So far we have implicitly assumed that an operator class deals with only one data type. While there certainly can be only one data type in a p…Operator Classes and Operator Families Operator InvocationsManual ChaptersPG184.2.5. Operator Invocations There are two possible syntaxes for an operator invocation: expression operator expression (binary infix operator) operator expression (unary prefix operator) whe…Operator Invocations Operator Optimization InformationManual ChaptersPG1836.15. Operator Optimization Information A PostgreSQL operator definition can include several optional clauses that tell the system useful things about how the operator behaves. These clause…Operator Optimization Information Operator PrecedenceManual ChaptersPG184.1.6. Operator Precedence Table 4.2 shows the precedence and associativity of the operators in PostgreSQL. Most operators have the same precedence and are left-associative. The precedence a…Operator Precedence OperatorsManual ChaptersPG184.1.3. Operators An operator name is a sequence of up to NAMEDATALEN-1 (63 by default) characters from the following list: + - * / < > = ~ ! @ # % ^ & | ` ? There are a few restrictions on o…Operators OperatorsManual ChaptersPG1810.2. Operators The specific operator that is referenced by an operator expression is determined using the following procedure. Note that this procedure is indirectly affected by the precede…Operators Operators and FunctionsManual ChaptersPG18F.22.2. Operators and Functions Type ltree has the usual comparison operators =, <>, <, >, <=, >=. Comparison sorts in the order of a tree traversal, with the children of a node sorted by la…Operators and Functions OptimizationManual ChaptersPG1830.1.3. Optimization LLVM has support for optimizing generated code. Some of the optimizations are cheap enough to be performed whenever JIT is used, while others are only beneficial for lon…Optimization OptimizerManual ChaptersPG18E.6.3.1.1. Optimizer Automatically remove some unnecessary table self-joins (Andrey Lepikhov, Alexander Kuzmenkov, Alexander Korotkov, Alena Rybakina) § This optimization can be disabled usi…Optimizer Optimizing PL/pgSQL FunctionsManual ChaptersPG1841.13.2.3. Optimizing PL/pgSQL Functions PostgreSQL gives you two function creation modifiers to optimize execution: “volatility” (whether the function always returns the same result when gi…Optimizing PL/pgSQL Functions Optional heapallindexed VerificationManual ChaptersPG18F.1.2. Optional heapallindexed Verification When the heapallindexed argument to B-Tree verification functions is true, an additional phase of verification is performed against the table asso…Optional heapallindexed Verification OptionsManual ChaptersPG18Options clusterdb accepts the following command-line arguments: -a--all Cluster all databases. [-d] dbname[--dbname=]dbname Specifies the name of the database to be clustered, when -a/--all …Options OptionsManual ChaptersPG18Options createdb accepts the following command-line arguments: dbname Specifies the name of the database to be created. The name must be unique among all PostgreSQL databases in this cluster…Options OptionsManual ChaptersPG18Options createuser accepts the following command-line arguments: username Specifies the name of the PostgreSQL user to be created. This name must be different from all existing roles in this…Options OptionsManual ChaptersPG18Options dropdb accepts the following command-line arguments: dbname Specifies the name of the database to be removed. -e--echo Echo the commands that dropdb generates and sends to the server…Options OptionsManual ChaptersPG18Options dropuser accepts the following command-line arguments: username Specifies the name of the PostgreSQL user to be removed. You will be prompted for a name if none is specified on the c…Options OptionsManual ChaptersPG18Options ecpg accepts the following command-line arguments: -c Automatically generate certain C code from SQL code. Currently, this works for EXEC SQL TYPE. -C mode Set a compatibility mode. …Options OptionsManual ChaptersPG18Options -A authmethod--auth=authmethod # This option specifies the default authentication method for local users used in pg_hba.conf (host and local lines). See Section 20.1 for an overview …Options OptionsManual ChaptersPG18Options -c--core-files Attempt to allow server crashes to produce core files, on platforms where this is possible, by lifting any soft resource limit placed on core files. This is useful in …Options OptionsManual ChaptersPG18Options The following command-line options control the content and format of the output. -a--data-only Dump only the data, not the schema (data definitions) or statistics. -c--clean Emit SQL…Options OptionsManual ChaptersPG18Options -d dbname--dbname=dbname Specifies the name of the database to connect to. The dbname can be a connection string. If so, connection string parameters will override any conflicting co…Options OptionsManual ChaptersPG18Options The following command-line options control what is checked: -a--all Check all databases, except for any excluded via --exclude-database. -d pattern--database=pattern Check databases …Options OptionsManual ChaptersPG18Options The following command-line options control the location and format of the output: -D directory--pgdata=directory Sets the target directory to write the output to. pg_basebackup will …Options OptionsManual ChaptersPG18Options The following command-line options are available: -D directory--pgdata=directory Specifies the directory where the database cluster is stored. -c--check Checks checksums. This is the…Options OptionsManual ChaptersPG18Options -d--debug Print lots of debug logging output on stderr. -k--link Use hard links instead of copying files to the synthetic backup. Reconstruction of the synthetic backup might be fast…Options OptionsManual ChaptersPG18Options To use pg_config, supply one or more of the following options: --bindir Print the location of user executables. Use this, for example, to find the psql program. This is normally also…Options