创建CONCURRENTLY索引时不会持有全表锁,这条指令分成两个步骤,第一部分创建索引并标记为不可用,这时候INSERT、UPDATE、DELETE操作已经开始维护索引了,但是查询不能使用索引。建立完毕后才会被标记为可用。 postgres=# CREATE CONCURRENTLY INDEX index ON tb(id); 可以手工设置索引的可用性。 UPDATE pg_index SET indis...
OPERATOR CLASS object_name USING index_method | [ PROCEDURAL ] LANGUAGE object_name | RULE rule_name ON table_name | SCHEMA object_name | SEQUENCE object_name | TRIGGER trigger_name ON table_name | TYPE object_name | VIEW object_name } IS 'text' COMMIT 提交当前事务。 COMMIT [ WORK | ...
1.TDSQL PostgreSQL版 提供的 index 类型:B-tree,Hash,GiST (Generalized Search Tree),SP-GiST (space-partitioned GiST),GIN (Generalized Inverted Index), BRIN (Block Range Index),目前不建议使用 Hash,通常情况下使用 B-tree。 2.建议 create 或 drop index 时,加 CONCURRENTLY 参数,达到与写入数据并发...
ERROR: cannot refresh materialized view "public.mat_view" concurrently HINT:CreateauniqueindexwithnoWHEREclauseononeormorecolumnsofthematerializedview. 物化视图需要一个唯一的列来支持并发刷新。这意味着您必须确定一个“主键”并创建一个唯一索引: demo=#CREATEUNIQUEINDEXidx_grpONmat_view (grp);CREATEINDEXde...
CREATEMATERIALIZED VIEW sales_testASSELECT*FROMsales; IMMV被创建后,会自动创建一些触发器,以便物化视图的基表被修改后立即更新物化视图的内容。 postgres=#SELECTcreate_immv('m','SELECT * FROM t0');NOTICE:couldnotcreatean indexonimmv"m"automaticallyDETAIL:This target list doesnothave all the primary ...
createindexidx_student_classid_stu_dateonstudent(stu_classid,stu_date); explainanalyze-- create or replace view view_student asselect/*+ parallel(s 4 hard) IndexOnlyScan(s idx_student_classid_stu_date) */sc.cls_id,count(distinctstu_date)fromstudent sleft joinstu_class scons.stu_classid...
...)|INDEXobject_name|LARGE OBJECT large_object_oid|OPERATOR op (left_operand_type, right_operand_type)|OPERATOR CLASSobject_nameUSING index_method|[PROCEDURAL]LANGUAGEobject_name|RULErule_nameONtable_name|SCHEMAobject_name|SEQUENCEobject_name|TRIGGERtrigger_nameONtable_name|TYPEobject_name|VIEWobject...
DROP VIEW postgres=# 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 8 索引 create table contacts(id int primary key,name varchar(20),phone varchar(32)[],address text); create index idx_contacts_name on contacts(name); ...
IndexStmt | InsertStmt /*插入数据SQL*/ | ListenStmt | RefreshMatViewStmt | LoadStmt | LockStmt | NotifyStmt | PrepareStmt | ReassignOwnedStmt | ReindexStmt | RemoveAggrStmt | RemoveFuncStmt | RemoveOperStmt | RenameStmt | RevokeStmt | RevokeRoleStmt | RuleStmt | SecLabelStmt | SelectStmt...
在线学习中心课程PostgreSQL 教程 1分钟 索引类型-局部索引 局部索引 是在表的子集上构建的索引;子集由一个条件表达式上定义。索引只包含满足条件的行。基础语法如下: CREATEINDEXindex_name ontable_name(conditional_expression); 上一节: 索引类型-唯一索引下一节: 索引类型-隐式索引...