ALTER TABLE table_name { ADD table_constraint | DROP CONSTRAINT constraint_name [ RESTRICT | CASCADE ] | OWNER TO new_owner | RENAME TO new_name | RENAME COLUMN column_name TO new_name | ALTER COLUMN column_name TYPE updated_varchar_data_type_size | ALTER COLUMN column_name ENCODE new_...
ALTER TABLE(DROP COLUMN) Amazon Redshift drops the column if it's not a primary key column. Otherwise, it resynchronizes the table. ALTER TABLE(SET LOGGED/UNLOGGED)If you change the table to logged, Amazon Redshift resynchronizes the table. If you change the table to unlogged, Amazon Red...
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...
WHERE c.relkind='r'--OPEN PAREN COLUMN LIST 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 table_...
drop table if exists temp_table_column_scripts; create temp table temp_table_column_scripts(script varchar); insert into temp_table_column_scripts select 'select ''' || column_name || ''' as column_name, ' || 'max(len(' || column_name ||')) as column_actual_len, ' || ...
Assert that an error is raised when trying to add a new column without theadd_new_columnsparameter (default isfalse) inappend,upsertoroverwrite[truncate,delete]mode. No errors instead are expected inoverwrite[drop, cascade]since the target table is dropped and recreated from scratch. ...
/* This is your table to be modified */CREATETABLEt_original (avarchar);INSERTINTOt_originalVALUES('v1'), ('v2');/* Here are the steps to add IDENTITY column */CREATETABLEt_new (idBIGINTIDENTITY(0,1), avarchar);ALTERTABLEt_new APPENDFROMt_original FILLTARGET;DROPTABLEt_original;ALTER...
Table | Column | Encoding ---+---+--- #my_temp_table | columb_a | lzo #my_temp_table | columb_b | bytedict (2 rows) 接下来,您可以将SELECT INTO语句转换为以下形式: BEGIN; CREATE TEMPORARY TABLE my_temp_table( column_a varchar(128) encode lzo, column...
需要对这个表中的一个字段设置为唯一约束： alter table table_name add unique (id); alter tabl ...
#my_temp_table | columb_a | lzo #my_temp_table | columb_b | bytedict (2 rows) 接下来,您可以将SELECT INTO语句转换为以下形式: BEGIN; CREATE TEMPORARY TABLE my_temp_table( column_a varchar(128) encode lzo, column_b char(4) encode bytedict) ...