使用新的 ALTER SORT KEY 命令,用户可以根据需要动态更改 Redshift 表排序键。Redshift 将负责在后台调整数据布局,而表仍然可以供用户查询。用户可以根据需要多次修改给定表的排序键,并且能同时更改多个表的排序键。有关ALTER SORT KEY 的更多信息,请参阅文档。 Redshift 1.0.10654 及更高版本提供此功能。请参阅 ...
有关ALTER SORTKEY 的更多信息,请参阅ALTER TABLE。 注意 如果您没有看到关于表的建议,这并不一定意味着当前配置是最好的。当没有足够的数据或排序的预期好处很小时,Advisor 不会提供建议。 Advisor 建议适用于特定的表,就算包含相同名称和数据类型的列的表也不一定适用。根据表中的数据和工作负载,共享列名的表可...
STL_SORT STL_SSHCLIENT_ERROR STL_STREAM_SEGS STL_TR_CONFLICT STL_UNDONE STL_UNIQUE STL_UNLOAD_LOG STL_USAGE_CONTROL STL_USERLOG STL_UTILITYTEXT STL_VACUUM STL_WINDOW STL_WLM_ERROR STL_WLM_RULE_ACTION STL_WLM_QUERY 快照数据的 STV 表 STV_ACTIVE_CURSORS STV_BLOCKLIST STV_CURSOR_CONFIGURATION...
distkey (column_a) -- Assuming you intend to join this table on column_a sortkey (column_b) -- Assuming you are sorting or grouping by column_b ; INSERT INTO my_temp_table SELECT column_a, column_b FROM my_table; COMMIT; 如果您使用CREATE TABLE LIKE语句创建一个临时分段表,则该分段表...
UNION SELECT c.oid::bigintastable_id,n.nspname AS schemaname, c.relname AS tablename,5AS seq,'('AS ddl FROM pg_namespace AS n INNER JOIN pg_class AS c ON n.oid=c.relnamespace WHERE c.relkind='r'--COLUMN LIST UNION SELECT ...
最近,我开始使用Redshift为数百万个数据点安装一个模式,如下所示: name varchar(100),) sortkey (name, timestamp);我想知道,通过将我的度量名映射到一个整数,并且只存储该整数,使其规范化(目前是varchar在传统的sql数据库中,这显然是肯定的,但我不确定Redshift是如何 浏览2提问于2014-06-20得票数 4 回答...
CREATE TABLE IF NOT EXISTS factCube ( index BIGINT, position SMALLINT, value FLOAT4, PRIMARY KEY (index, position) ) DISTKEY (index) SORTKEY (index, position); We did not apply any specific codecs for Redshift as well, and were surprised to see that Redshift could not use any default...
s workload. If Amazon Redshift determines that applying a key will improve cluster performance, it is designed to alter tables without requiring administrator intervention. Additional features like Automatic Vacuum Delete, Automatic Table Sort, and Automatic Analyze are designed to eliminate the need ...
root@localhost [testdb]>alter table t1 modify c2 varchar(90); root@localhost [testdb]>desc t1; +---+---+---+---+---+---+ | Field | Type | Null | Key | Default | Extra | +---+---+---+---+---+---+ | c1
Redshift doesn't support indexes. Instead, each table has a sort key, which determines how rows are ordered when the data is loaded. When you insert, update, or copy data in a Redshift table, new rows get added to an unsorted region, and are sorted only when the table is vac...