Postgresql 中文操作指南
54.15. pg_prepared_statements #
pg_prepared_statements 视图显示当前会话中提供的所有已准备好的语句。有关已准备好的语句的详细信息，请参见 PREPARE 。
The pg_prepared_statements view displays all the prepared statements that are available in the current session. See PREPARE for more information about prepared statements.
pg_prepared_statements 为每个已准备好的语句包含一行。当创建新的已准备好的语句时，会向视图添加行，而在释放已准备好的语句时会删除行（例如，通过 DEALLOCATE 命令）。
pg_prepared_statements contains one row for each prepared statement. Rows are added to the view when a new prepared statement is created and removed when a prepared statement is released (for example, via the DEALLOCATE command).
Table 54.15. pg_prepared_statements Columns
Table 54.15. pg_prepared_statements Columns
Column Type Description |
name text The identifier of the prepared statement |
statement text The query string submitted by the client to create this prepared statement. For prepared statements created via SQL, this is the PREPARE statement submitted by the client. For prepared statements created via the frontend/backend protocol, this is the text of the prepared statement itself. |
prepare_time timestamptz The time at which the prepared statement was created |
parameter_types regtype[] The expected parameter types for the prepared statement in the form of an array of regtype. The OID corresponding to an element of this array can be obtained by casting the regtype value to oid. |
result_types regtype[] The types of the columns returned by the prepared statement in the form of an array of regtype. The OID corresponding to an element of this array can be obtained by casting the regtype value to oid. If the prepared statement does not provide a result (e.g., a DML statement), then this field will be null. |
from_sql bool true if the prepared statement was created via the PREPARE SQL command; false if the statement was prepared via the frontend/backend protocol |
generic_plans int8 Number of times generic plan was chosen |
custom_plans int8 Number of times custom plan was chosen |
pg_prepared_statements 试图只读。
The pg_prepared_statements view is read-only.