Often the best choice will be to partition by the column or set of columns which most commonly appear in WHERE clauses of queries being executed on the partitioned table. WHERE clauses that are compatible with the partition bound constraints can be used to prune unneeded partitions. However, ...
CREATETABLEfoo (fooidint, foosubidint, fooname text);CREATEFUNCTIONgetfoo(int)RETURNSSETOF fooAS$$SELECT*FROMfooWHEREfooid=$1; $$LANGUAGESQL;SELECT*FROMgetfoo(1)ASt1;SELECT*FROMfooWHEREfoosubidIN(SELECTfoosubidFROMgetfoo(foo.fooid) zWHEREz.fooid=foo.fooid );CREATEVIEWvw_getfooASSELECT...
复制 [root@EULER1~]# su-pg1-c"psql -Upostgres -p 5432 -h 192.168.123.60"Passwordforuser postgres:psql(12.5)Type"help"forhelp.postgres=# create tablespace mytbs location'/opt/custome-tablespace';CREATETABLESPACEpostgres=# \db+Listoftablespaces Name|Owner|Location|Access privileges|Options|Size|...
postgres=#createtablet_list(idint, info text, crt_timetimestamp)partitionbylist (mod(hashtext(info),4) );CREATETABLE 2.2 分区 postgres=#createtablet_list_0partitionoft_list (idprimarykey, info , crt_time )forvaluesin(0);CREATETABLEpostgres=#createtablet_list_1partitionoft_list (idprimarykey,...
outcursor IN OUT mycursor ) IS BEGIN OPEN outcursor FOR SELECT*FROM Student WHERE ROWNUM<10; RETURN; END myproc; END; 包头代码: CREATE OR REPLACE PACKAGE MYPACKAGE AS type empcursor is ref cursor; PROCEDURE queryempList(dno in NUMBER,empList out empcursor); ...
该函数主要用于判断元组的合法性,即元组是否符合where条件 bool ExecQual(List *qual, ExprContext *econtext, bool resultForNull) { bool result; MemoryContext oldContext; ListCell *l; /* * debugging stuff */ EV_printf("ExecQual: qual is "); EV_nodeDisplay(qual); EV_printf("\n"); /* *...
3、创建LIST分区 dolanguageplpgsql $$declarebeginforsidin1..60loopexecuteformat('create table p%s partition of p for values in (%s)', sid, sid);endloop;end; $$; 分区表支持insert into on conflict语法 upsert, merge insert, insert on conflict 合并写的语法 ...
The provider architecture (32-bit or 64-bit) needs to match the architecture of the product where you intent to use the connector. When installing, make sure that you select NpgSQL GAC Installation to ensure NpgSQL itself is added to your machine. The minimun supported PostgreSQL database ...
target_el=oid,target_el=relname归约符合target_list,即归约; target_list符合归约条件opt_target_list,也进行归约。 scanner发现from,移进from未符合归约条件,继续移进pg_class,符合from_list->table_ref->relation_expr->qualified_name->ColId->IDENT,符合归约条件,则返回from_list; scanner发现where 符合...
Select型查询语句SelectStmt定义在src/include/nodes/parsenodes.h中,如下其包含目标列域targetList、from子句fromClause、where条件whereClause。where条件whereClause结构体执行A_Expr结构体(有如下成员NodeTag type、A_Expr_Kind kind、List *name、Node *lexper、Node *rexpr、int location),其中name指明了这是等号...