设置存储引擎
存储引擎会对数据库整体效率和性能具有巨大影响,请根据实际需求选择适当的存储引擎。用户可使用WITH ( [ORIENTATION | STORAGE_TYPE] [= value] [, ... ] )为表或索引指定一个可选的存储参数。参数的详细描述如下所示:
ORIENTATION |
STORAGE_TYPE |
ROW(缺省值):表的数据将以行式存储。 |
[USTORE(缺省值)|ASTORE|空] |
如果ORIENTATION指定为ROW,且STORAGE_TYPE为空的情况下创建出的表类型取决于GUC参数enable_default_ustore_table(取值为on/off,默认情况为on):如果参数设置为on,创建出的表为Ustore类型;如果为off,创建出的表为Astore类型。
gaussdb=# CREATE TABLE TEST(a int); gaussdb=# \d+ test Table "public.test" Column | Type | Modifiers | Storage | Stats target | Description --------+---------+-----------+---------+--------------+------------- a | integer | | plain | | Has OIDs: no Options: orientation=row, compression=no, storage_type=USTORE gaussdb=# CREATE TABLE TEST1(a int) with(orientation=row, storage_type=ustore); gaussdb=# \d+ test1 Table "public.test1" Column | Type | Modifiers | Storage | Stats target | Description --------+---------+-----------+---------+--------------+------------- a | integer | | plain | | Has OIDs: no Options: orientation=row, storage_type=ustore, compression=no gaussdb=# CREATE TABLE TEST2(a int) with(orientation=row, storage_type=astore); gaussdb=# \d+ test2 Table "public.test2" Column | Type | Modifiers | Storage | Stats target | Description --------+---------+-----------+---------+--------------+------------- a | integer | | plain | | Has OIDs: no Options: orientation=row, storage_type=astore, compression=no gaussdb=# create table test4(a int) with(orientation=row); gaussdb=# \d+ List of relations Schema | Name | Type | Owner | Size | Storage | Description --------+-------+-------+-----------+---------+------------------------------------------------------+------------- public | test4 | table | l30048445 | 0 bytes | {orientation=row,compression=no,storage_type=USTORE} | (1 row) gaussdb=# show enable_default_ustore_table; enable_default_ustore_table ----------------------------- on (1 row)