创建唯一索引似乎失败了，但无论如何都创建了？

Question

正在创建唯一（多列）索引，但它失败了，因为 table 中已经存在非唯一行。然而，索引似乎无论如何都被创建了...

这是我正在使用的SQL：

CREATE UNIQUE INDEX CONCURRENTLY IF NOT EXISTS company_by_code ON public.company USING BTREE("owner","org","code")

这导致 Postgresql 的以下响应：

ERROR:  could not create unique index "company_by_code"
DETAIL:  Key (owner, org, code)=(ABC, DEF, XYZ) is duplicated.
SQL state: 23505

然而，即使 CREATE 语句似乎出错了，INDEX 似乎还是被创建了。

这是可以预料的吗？

Answer 1

这是documented in the manual

If a problem arises while scanning the table, such as a deadlock or a uniqueness violation in a unique index, the CREATE INDEX command will fail but leave behind an “invalid” index. This index will be ignored for querying purposes because it might be incomplete; however it will still consume update overhead. The psql \d command will report such an index as INVALID

如果您不想要这种行为，请不要使用 CONCURRENTLY

创建唯一索引似乎失败了，但无论如何都创建了？

Creating unique index seems to fail, but is created anyway?

postgresql

indexing

unique-index