+ linkend="runtime-config-wal-recovery-target"/>. Parameters from
linkend="runtime-config-replication-standby"/> will not be used.
given decimal precision. The precision used is the standard number of
digits for the type (FLT_DIG
or DBL_DIG as appropriate) reduced according to the
- value of this parameter. (For example, specifying -1 will cause float4
- values to be output rounded to 5 significant digits, and float8 values
+ value of this parameter. (For example, specifying -1 will cause
+ float4 values to be output rounded to 5 significant
+ digits, and float8 values
rounded to 14 digits.) This format is slower and does not preserve all
the bits of the binary float value, but may be more human-readable.
- Reports the name of the SSL library that this PostgreSQL server was
- built with (even if SSL is not currently configured or in use on this
- instance), for example OpenSSL, or an empty string
- if none.
+ Reports the name of the SSL library that this
+
PostgreSQL server was built with (even if
+ SSL is not currently configured or in use on this instance), for
+ example OpenSSL, or an empty string if none.
- The third option is to declare a sql identifier linked to
+ The third option is to declare a SQL identifier linked to
the connection, for example:
EXEC SQL AT connection-name DECLARE statement-name STATEMENT;
EXEC SQL PREPARE statement-name FROM :dyn-string;
- Once you link a sql identifier to a connection, you execute a dynamic SQL
- without AT clause.
+ Once you link a SQL identifier to a connection, execute dynamic SQL
+ statements using this identifier without the AT clause.
bytea
- The handling of the bytea type is also similar to
- the VARCHAR. The definition on an array of type
+ The handling of the bytea type is similar to
+ that of VARCHAR. The definition on an array of type
bytea is converted into a named struct for every
variable. A declaration like:
struct bytea_var { int len; char arr[180]; } var;
The member arr hosts binary format
- data. It also can handle even '\0' as part of
- data unlike VARCHAR.
+ data. It can also handle '\0' as part of
+ data, unlike VARCHAR.
The data is converted from/to hex format and sent/received by
ecpglib.
DECLARE STATEMENT
- declares SQL statement identifier associated with connection
+ declares a SQL statement identifier associated with connection
Description
- DECLARE STATEMENT declares SQL statement identifier.
- SQL statement identifier is associated with connection.
+ DECLARE STATEMENT declares a SQL statement identifier
+ to be associated with connection.
- DECLARE CURSOR with a SQL statement identifier can be written before PREPARE.
+ DECLARE CURSOR with an SQL statement identifier
+ can be written before PREPARE.
A database connection name established by the CONNECT command.
- If AT clause is omitted, an SQL statement identifier is associated with the DEFAULT connection.
+ If the AT clause is omitted, the SQL statement
+ identifier is associated with the DEFAULT connection.
statement_name
- The name of a SQL statement identifier, either as an SQL identifier or a host variable.
+ The name of the SQL statement identifier, either as an SQL identifier
+ or a host variable.
Notes
- AT clause can be used at other dynamic SQL statements. The following table
- gives the connected database when AT clause is used at DECLARE STATEMENT
- and other dynamic statements.
+ The AT clause can be used with both
+ DECLARE STATEMENT and other dynamic SQL statements.
+ The following table illustrates how it affects the selected database
+ connection.
Scenario
|
- Using Scenario
+ Usage Scenario
- Declare Statement
+ DECLARE STATEMENT
Other Dynamic Statements
- Executed Database
+ Target Database
1
- Without AT clause
+ Without AT
- Without AT clause
+ Without AT
Default connection
2
- Using AT clause connecting at con1
+ With AT that connects to con1
- Without AT clause
+ Without AT
con1
3
- Using AT clause connecting at con1
+ With AT that connects to con1
- Using AT clause connecting at con2
+ With AT that connects to con2
con1
4
- Without AT clause
+ Without AT
- Using AT clause connecting at con2
+ With AT that connects to con2
con2
- In scenario 4, DECLARE STATEMENT will be ignored.
+ In scenario 4, DECLARE STATEMENT will be ignored.
returning the connection's previous setting.
In TERSE mode, returned messages include
severity, primary text, and position only; this will normally fit on a
- single line. The default mode produces messages that include the above
- plus any detail, hint, or context fields (these might span multiple
- lines). The VERBOSE mode includes all available
- fields. The SQLSTATE mode includes only the
- error severity and the SQLSTATE error code, if one is
- available (if not, the output is like TERSE
- mode).
+ single line. The DEFAULT mode produces messages
+ that include the above plus any detail, hint, or context fields (these
+ might span multiple lines). The VERBOSE mode
+ includes all available fields. The SQLSTATE
+ mode includes only the error severity and the SQLSTATE
+ error code, if one is available (if not, the output is like
+ TERSE mode).
only present if the HEAP_HASNULL bit is set in
t_infomask. If it is present it begins just after
the fixed header and occupies enough bytes to have one bit per data column
- (that is, t_natts bits altogether). In this list of bits, a
+ (that is, the number of bits that equals the attribute count in
+ t_infomask2). In this list of bits, a
1 bit indicates not-null, a 0 bit is a null. When the bitmap is not
present, all columns are assumed not-null.
The object ID is only present if the HEAP_HASOID_OLD bit
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