unlogged table是为临时数据设计的,写入性能较高,但是当postgresql进程崩溃时会丢失数据。 创建一张普通表test和一张unlogged表test,测试性能情况 普通表: test=#createtabletest(aint);CREATETABLEtest=# \timing Timingison. test=#insertintotestselectgenerate_series(1,1000000);INSERT01000000Time:3603.715ms unlogged...
unlogged table是为临时数据设计的,写入性能较高,但是当postgresql进程崩溃时会丢失数据。 创建一张普通表test和一张unlogged表test,测试性能情况 普通表: test=#createtabletest(aint);CREATETABLEtest=# \timing Timingison. test=#insertintotestselectgenerate_series(1,1000000);INSERT01000000Time:3603.715ms unlogged...
TEMPORARYorTEMP如果被指定,该表被创建为一个临时表。详见 CREATE TABLE。 UNLOGGED如果被指定,该表会被创建为一个LOGGED表。 new_table要创建的表的名字(可以是模式限定的)。 说明 所有其他参数在SELECT中有详细描述。 说明 CREATE TABLE AS在功能上与SELECT INTO相似。CREATE TABLE AS是被推荐的语法,因为这种形式...
SELECT INTO从一个查询的结果中定义一个新表。SELECT [ ALL | DISTINCT [ ON ( expression [, ...] ) ] ] * | expression [ AS output_name ] [, ...] INTO [ TEMPORARY | TEMP ] [ TABLE ] new_table [ FROM from_item [, ...] ] [ WHERE condition ] [ GROUP BY expression [, .....
- Next, it creates a new table or temporary table. - Finally, it inserts the selected data from the original table and puts it into the newly created table. Let’s understand the SELECT INTO statement via the following examples. Example 1: Copying Data to Regular Postgres Table ...
插入查询结果到临时表:使用INSERT INTO语句将查询结果插入到临时表中。 例如: 代码语言:txt 复制 INSERT INTO temp_table (name, age) SELECT name, age FROM users WHERE age > 18; 代码语言:txt 复制 以上步骤将会将查询结果中满足条件的数据插入到临时表中,临时表可以在当前会话中进行查询和操作。
[ ONLY ] table_name [ * ] [ [ AS ] alias [ ( column_alias [, ...] ) ] ] SQL 语句 一个SQL 语句通常包含了关键字、标识符(字段)、常量、特殊符号等,下面是一个简单的 SQL 语句: SELECT id, name FROM runoob SELECTid, nameFROMrunoob ...
IS 'pg_class create table'; CREATE TEMPORARY TABLE tempory_table( id int, system_info text ); CREATE TABLE tempory_table ( id int, system_info text, type_d varchar(10) ); insert into tempory_table (id,system_info) values (1,'system_info'); ...
First, create a table named customers: CREATE TABLE customers( id SERIAL PRIMARY KEY, name VARCHAR NOT NULL ); Second, create a temporary table with the same name: customers CREATE TEMP TABLE customers( customer_id INT ); Now, query data from the customers table: SELECT * FROM customers; ...
postgres=# \help SELECT Command: SELECT Description: retrieve rows from a table or view Syntax: [ WITH [ RECURSIVE ] with_query [, ...] ] SELECT [ ALL | DISTINCT [ ON ( expression [, ...] ) ] ] [ * | expression [ [ AS ] output_name ] [, ...] ] ...