CREATE OR REPLACE FUNCTION get_multiple_result_sets() RETURNS SETOF refcursor AS $$ DECLARE cur1 refcursor; cur2 refcursor; BEGIN -- 打开第一个游标并返回 OPEN cur1 FOR SELECT * FROM table1; RETURN NEXT cur1; -- 打开第二个游标并返回 OPEN cur2 FOR SELECT * FROM table2; RETURN NEXT c...
PostgreSQL11创建或替换过程GetMultipleResultSets(INOUT ref1 refcursor，INOUT ref2 refcursor)；使用Npgsq...
a Parallel Append node can have both partial and non-partial child plans. Non-partial children will be scanned by only a single process, since scanning them more than once would produce duplicate results. Plans that involve appending multiple results sets can therefore achieve...
*/ resultSlot = ExecProject(projInfo, &isDone); if (isDone != ExprEndResult) { node->ps.ps_TupFromTlist = (isDone == ExprMultipleResult); return resultSlot; } } else { /* * Here, we aren't projecting, so just return scan tuple. */ return slot; } } else InstrCountFiltered1(n...
Union – combine result sets of multiple queries into a single result set. Intersect –combine the result sets of two or more queries and return a single result set containing rows that appear in both result sets. Except –return the rows from the first query that do not appear in the ...
PL/pgSQL functions can return cursors to the caller. This is useful to return multiple rows or columns, especially with very large result sets. To do this, the function opens the cursor and returns the cursor name to the caller (or simply opens the cursor using a portal name specified by...
Sets the number of parallel continuous query combiner processes to use for each database. A higher number will utilize multiple cores and increase throughput until we’re I/O bound. Default: 1. 3、pipelinedb.commit_interval 每个combiner进程,会先将合并的结果数据HOLD在combiner_work_mem,以提高性能...
For any SQL command that does not return rows, for example INSERT without a RETURNING clause, you can execute the command within a PL/pgSQL function just by writing the command. To evaluate an expression or SELECT query but discard the result, use: ...
return 7; when 'AccessExclusiveLock' then return 8; else return 0; end case; end; $$ language plpgsql strict; 修改查询语句,按锁级别排序: with t_wait as (select a.mode,a.locktype,a.database,a.relation,a.page,a.tuple,a.classid,a.objid,a.objsubid, a.pid,a.virtualtransaction,a....
Result sets of time series queries must be sorted by time. The following example code shows a metric column. SELECT $__timeGroup("time_date_time",'5m'), min("value_double"), 'min' as metric FROM test_data WHERE $__timeFilter("time_date_time") GROUP BY time ORDER BY time ...