postgres@[local]:5432=#\c test pguserYou are now connected to database"test"as user"pguser".test@[local]:5432=#select current_database;ERROR: column"current_database"does not exist LINE 1: select current_database; ^test@[local]:5432=#select current_database();current_database ---test...
ObjectType String 是 支持使用的数据库对象类型有:account,database,schema,sequence,procedure,type,function,table,view,matview,column。示例值:database ObjectName String 是 所描述的数据库对象名称示例值:test_database DatabaseName String 否 所要描述的数据库对象,所属的数据库名称。当描述对象类型不为data...
typedef struct ExprState{NodeTag type;uint8 flags;/* bitmask of EEO_FLAG_* bits, see above *//* * Storage for result value of a scalar expression, or for individual * column results within expressions built by ExecBuildProjectionInfo(). */#defineFIELDNO_EXPRSTATE_RESNULL2bool resnull;#d...
指catalog或者user_catalog_table = true的表,不允许修改列的数据类型。 postgres=# \d+ cTable"public.c"Column|Type| Modifiers |Storage| Stats target | Description---+---+---+---+---+---id |integer| | plain | |info|text| | extended | | c |text| | extended | |ReplicaIdentity:FUL...
In the rest of the document, we have discussed each of the PostgreSQL Data Types based on PostgreSQL 9.1 Version.Category - Numeric TypesNameDescriptionStorage Size Range smallint Stores whole numbers, small range. 2 bytes -32768 to +32767 integer Stores whole numbers.Use this when you want ...
Column | Type | Collation | Nullable | Default | Storage | Stats target | Description ---+---+---+---+---+---+---+--- id | integer | | | | plain | | info | text | | | | extended | | crt_time | timestamp without time zone | |...
column_name:支持指定列的垃圾回收。 PARALLEL 这里特意拿出来说一下,这个参数官方在Postgresql 13版本才加入,个人感觉是受到Mysql的“刺激”加入的,作用是指定垃圾回收线程的并发数,用户可以手动指定非零值,当然这个值不是自由指定的,官方存在对应的“最大值”限制胡乱传参。
Most of these plan node types have the additional ability to do selection (discarding rows that do not meet a specified Boolean condition) and projection (computation of a derived column set based on given column values, that is, evaluation of scalar expressions where needed). One of the ...
postgres=#altertabletestaltercolumninfosetstorage plain; postgres=#insertintotestselectnow()fromgenerate_series(1,1000); postgres=#selectctidfromtest limit1000; 分别在3个物理块设备上创建3个表空间目录,同时在数据库中创建表空间。 tbs1, tbs2, tbs3. ...
{ "partitionColumnName": "<partition_column_name>", "partitionUpperBound": "<upper_value_of_partition_column (optional) to decide the partition stride, not as data filter>", "partitionLowerBound": "<lower_value_of_partition_column (optional) to decide the partition stride, not as data ...