CREATE[ORREPLACE]FUNCTIONname([[argmode][argname]argtype[{DEFAULT|=}default_expr][,...]])[RETURNSrettype|RETURNSTABLE(column_name column_type[,...])]{LANGUAGElang_name|TRANSFORM{FORTYPEtype_name}[,...]|WINDOW|IMMUTABLE|STABLE|VOLATILE|[NOT]LEAKPROOF|CALLEDONNULLINPUT|RETURNSNULLONNULLINPUT|...
1) 启动数据库pg_ctl start 2) 创建数据库 arch createdb arch 3) 创建表并插入记录psql arch arch=# create table tb(a int); arch=# insert into tb(a) values(1); 4) 创建备份 arch=# select pg_start_backup('baseline'); pg_start_backup- 0/E000060 (1 row) 观察归档日志目录下的归档文件...
SELECT*FROMpg_roles rORDERBYr.rolname;SELECT*FROMpg_rolesWHERErolname='postgres';SELECT*FROMpg_authid; (3)查看某用户的表权限 SELECT*FROMinformation_schema.table_privilegesWHEREgrantee='your_user_name'; (4)查看某用户在某表的列上的权限 SELECT*FROMinformation_schema.column_privilegesWHEREgrantee='yo...
ALTER TABLE pgweb ADD COLUMN textsearchable_index_col tsvector GENERATED ALWAYS AS (to_tsvector('english', coalesce(title, '') || ' ' || coalesce(body, ''))) STORED; 然后创建一个GIN索引来加速搜索: CREATE INDEX textsearch_idx ON pgweb USING GIN(textsearchable_index_col); 准备好执行一个...
{ FIRST | NEXT } [ count ] { ROW | ROWS } ONLY ] [ FOR { UPDATE | NO KEY UPDATE | SHARE | KEY SHARE } [ OF table_name [, ...] ] [ NOWAIT | SKIP LOCKED ] [...] ] from_item 可以是以下选项之一: [ ONLY ] table_name [ * ] [ [ AS ] alias [ ( column_alias [,...
alter table toast_t1 alter column dd set storage main; /d+ toast_1 Column | Type | Storage | ---+---+---+- dd | character varying | main | Access method: heap 查看Toast表的名字 --查看tost表的oid testdb=# select relname,relfilenode,reltoastrelid from pg_class where relname='...
column? --- t (1 row) postgres=# select to_tsvector('There was a crooked man, and he walked a crooked mile') @@ to_tsquery('man & (going | running)'); ?column? --- f (1 row) 关于全文检索的知识,这些就已经够了。我们将在下一篇讨论 GIN 索引时,再深入讨论全文检索。 RD-树 为了...
select*from<table_name>where<column_name>>'Tom'collate"C"; 使用本土化索引进行排序 排序语句中的collate与索引的collate保持一致,才能使用这个索引进行排序。命令如下: createindex idxaon<table_name>(<column_name>collate"en_US"); explainselect*from<table_name>orderby<column...
CREATE TRIGGER trigger_name BEFORE INSERT OR UPDATE ON table FOR EACH ROW EXECUTE PROCEDUREtsvector_update_trigger(tsv_column, 'parser_name', field); // 创建一个更新分词触发器 这样,再进行查询时就可以直接使用 SELECT * FROM table WHERE tsv_column @@ 'keyword' 了。 这里需要注意,这时候在往表...
select [level], column, expr... from table [where condition] start with condition connect by [prior column1= column2 | column1 = prior column2]; 1. 2. 3. 4. 5. 2 语法解释 层次查询是通过start with和connect by子句标识的: 1.其中level关键字是可选的,表示等级,1表示root,2表示root的chi...