要在不阻塞表的情况下做到这一点,我需要使用DROP INDEX CONCURRENTLY。在文献资料 for CREATE INDEX CONCURRENTLY中有一个注释:
常规索引生成允许同一表上的其他常规索引生成同时发生,但一次只能在一个表上生成一个并发索引。在文献资料 for DROP INDEX CONCURRENTLY中,我没有看到类似的注释。同时在同一张表上运行多个DROP INDEX CONCURRENTLY's是否安全?
use m.SQL("CREATE TABLE ...") to make schema update "CREATE UNIQUE INDEX CONCURRENTLYIF NOT EXISTS uniq_email ON users (email) WHERE status_id=1;" +
"CREATE UNIQUE INDEX CONCURRENTLY// use m.SQL("
我看过文档,它说如果它返回1:device can concurrently copy memory between host and device while executing a kernel
如果是2:device can concurrently copy memory between host and device in both directions and execute a kernel