PostgreSQL has a rich set of native data types available to users. Users can add new types to PostgreSQL using the CREATE TYPE command. PostgreSQL有一组丰富的本地数据类型可供用户使用。用户可以使用CREATE TYPE命令向PostgreSQL添加新类型。Each data type has an external representation determined by its...
\drds [PATRN1 [PATRN2]] list per-database role settings \ds[S+] [PATTERN] list sequences \dt[S+] [PATTERN] list tables \dT[S+] [PATTERN] list data types \du[+] [PATTERN] list roles \dv[S+] [PATTERN] list views \dE[S+] [PATTERN] list foreign tables \dx[+] [PATTERN] li...
postgres=# \df List of functionsSchema | Name | Result data type | Argument data types | Type---+---+---+---
分区键离散,可以使用PARTITION BY LIST。按字符串匹配决定落入哪个分区。 分区键连续,比如整形、日期等,可以使用PARTITION BY RANGE。 分区键数据随机无规律或规律简单,可以使用PARTITION BY HASH,用hash函数打散数据。 分区键数据随机有规律,规律复杂,可以使用多级混合分区,使数据平均分散、减少耦合。 每个分区都是一个...
For a list of the supported data types, seeData types. These PostgreSQL data types are not supported in Amazon Redshift. Arrays BIT, BIT VARYING BYTEA Composite Types Enumerated Types Geometric Types (Amazon Redshift implementation of geometric types differs from PostgreSQL) ...
\deu[+] [PATTERN] list user mappings \dew[+] [PATTERN] list foreign-data wrappers \df[anptw][S+] [PATRN] list [only agg/normal/procedures/trigger/window] functions \dF[+] [PATTERN] list text searchconfigurations\dFd[+] [PATTERN] list text search dictionaries ...
List of data types Schema | Name | Description ---+---+--- public | user_enum | (1 row) test=# select oid from pg_type where typname='user_enum'; oid --- 17453 (1 row) test=# CREATE FOREIGN TABLE ft1 ( test(# c0 int, test(# c1 int NOT NULL...
| | \dT[S+] [pattern] | List data types | | \db[+] [pattern] | List tablespaces. | | \ddp [pattern] | Lists default access privilege settings. | | \df[+] [pattern] | List functions. | | \di[+] [pattern] | List indexes. | | \dm[+] [pattern] | List materialized ...
除了传统的基于trigger和rule的分区,PostgreSQL 10开始已经内置了分区功能(目前仅支持list和range),使用pg_pathman则支持hash分区。 从性能角度,目前最好的还是pg_pathman分区。 但是,传统的分区手段,依旧是最灵活的,在其他方法都不奏效时,可以考虑传统方法。
基因倒排索引(Generalized Inverted Index) 存储了一个Key/posting list 的结构,Key是唯一键。posting list里面存储了Key出现的行。 GIN索引的创建方式如下: CREATE INDEX GIN_idx1 ON student USING GIN (to_tsvector('english', stud_name)); GIN 索引显然是给搜索优化做准备的,GIN 索引是反转索引,它可以处理...