array_nulls (boolean)
      
      
        This controls whether the array input parser recognizes
        unquoted NULL as specifying a null array element.
        By default, this is on, allowing array values containing
        null values to be entered.  However, PostgreSQL versions
        before 8.2 did not support null values in arrays, and therefore would
        treat NULL as specifying a normal array element with
        the string value “NULL”.  For backward compatibility with
        applications that require the old behavior, this variable can be
        turned off.
       
        Note that it is possible to create array values containing null values
        even when this variable is off.
       
backslash_quote (enum)
      
      
      
        This controls whether a quote mark can be represented by
        \' in a string literal.  The preferred, SQL-standard way
        to represent a quote mark is by doubling it ('') but
        PostgreSQL has historically also accepted
        \'. However, use of \' creates security risks
        because in some client character set encodings, there are multibyte
        characters in which the last byte is numerically equivalent to ASCII
        \.  If client-side code does escaping incorrectly then a
        SQL-injection attack is possible.  This risk can be prevented by
        making the server reject queries in which a quote mark appears to be
        escaped by a backslash.
        The allowed values of backslash_quote are
        on (allow \' always),
        off (reject always), and
        safe_encoding (allow only if client encoding does not
        allow ASCII \ within a multibyte character).
        safe_encoding is the default setting.
       
        Note that in a standard-conforming string literal, \ just
        means \ anyway.  This parameter only affects the handling of
        non-standard-conforming literals, including
        escape string syntax (E'...').
       
default_with_oids (boolean)
      
      
        This controls whether CREATE TABLE and
        CREATE TABLE AS include an OID column in
        newly-created tables, if neither WITH OIDS
        nor WITHOUT OIDS is specified. It also
        determines whether OIDs will be included in tables created by
        SELECT INTO. The parameter is off
        by default; in PostgreSQL 8.0 and earlier, it
        was on by default.
       
        The use of OIDs in user tables is considered deprecated, so
        most installations should leave this variable disabled.
        Applications that require OIDs for a particular table should
        specify WITH OIDS when creating the
        table. This variable can be enabled for compatibility with old
        applications that do not follow this behavior.
       
escape_string_warning (boolean)
      
      
      
        When on, a warning is issued if a backslash (\)
        appears in an ordinary string literal ('...'
        syntax) and standard_conforming_strings is off.
        The default is on.
       
        Applications that wish to use backslash as escape should be
        modified to use escape string syntax (E'...'),
        because the default behavior of ordinary strings is now to treat
        backslash as an ordinary character, per SQL standard.  This variable
        can be enabled to help locate code that needs to be changed.
       
lo_compat_privileges (boolean)
      
      
        In PostgreSQL releases prior to 9.0, large objects
        did not have access privileges and were, therefore, always readable
        and writable by all users.  Setting this variable to on
        disables the new privilege checks, for compatibility with prior
        releases.  The default is off.
        Only superusers can change this setting.
       
Setting this variable does not disable all security checks related to large objects — only those for which the default behavior has changed in PostgreSQL 9.0.
operator_precedence_warning (boolean)
      
      
        When on, the parser will emit a warning for any construct that might
        have changed meanings since PostgreSQL 9.4 as a result
        of changes in operator precedence.  This is useful for auditing
        applications to see if precedence changes have broken anything; but it
        is not meant to be kept turned on in production, since it will warn
        about some perfectly valid, standard-compliant SQL code.
        The default is off.
       
See Section 4.1.6 for more information.
quote_all_identifiers (boolean)
      
      
        When the database generates SQL, force all identifiers to be quoted,
        even if they are not (currently) keywords.  This will affect the
        output of EXPLAIN as well as the results of functions
        like pg_get_viewdef.  See also the
        --quote-all-identifiers option of
        pg_dump and pg_dumpall.
       
standard_conforming_strings (boolean)
      
      
      
        This controls whether ordinary string literals
        ('...') treat backslashes literally, as specified in
        the SQL standard.
        Beginning in PostgreSQL 9.1, the default is
        on (prior releases defaulted to off).
        Applications can check this
        parameter to determine how string literals will be processed.
        The presence of this parameter can also be taken as an indication
        that the escape string syntax (E'...') is supported.
        Escape string syntax (Section 4.1.2.2)
        should be used if an application desires
        backslashes to be treated as escape characters.
       
synchronize_seqscans (boolean)
      
      
        This allows sequential scans of large tables to synchronize with each
        other, so that concurrent scans read the same block at about the
        same time and hence share the I/O workload.  When this is enabled,
        a scan might start in the middle of the table and then “wrap
        around” the end to cover all rows, so as to synchronize with the
        activity of scans already in progress.  This can result in
        unpredictable changes in the row ordering returned by queries that
        have no ORDER BY clause.  Setting this parameter to
        off ensures the pre-8.3 behavior in which a sequential
        scan always starts from the beginning of the table.  The default
        is on.
       
transform_null_equals (boolean)
      
      
      
        When on, expressions of the form expr =
        NULLNULL =
        ) are treated as
        exprexpr IS NULLexpr evaluates to the null value,
        and false otherwise. The correct SQL-spec-compliant behavior of
        expr = NULLoff.
       
        However, filtered forms in Microsoft
        Access generate queries that appear to use
        expr = NULLexpr = NULL
        Note that this option only affects the exact form = NULL,
        not other comparison operators or other expressions
        that are computationally equivalent to some expression
        involving the equals operator (such as IN).
        Thus, this option is not a general fix for bad programming.
       
Refer to Section 9.2 for related information.