查询缓慢的INFORMATION_SCHEMA
我们有一个.NET Windows应用程序,它在login时运行以下查询来获取有关数据库的一些信息: SELECT t.TABLE_NAME, ISNULL(pk_ccu.COLUMN_NAME,'') PK, ISNULL(fk_ccu.COLUMN_NAME,'') FK FROM INFORMATION_SCHEMA.TABLES t LEFT JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS pk_tc ON pk_tc.TABLE_NAME = t.TABLE_NAME AND pk_tc.CONSTRAINT_TYPE = 'PRIMARY KEY' LEFT JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE pk_ccu ON pk_ccu.CONSTRAINT_NAME = pk_tc.CONSTRAINT_NAME LEFT JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS fk_tc ON fk_tc.TABLE_NAME = t.TABLE_NAME AND fk_tc.CONSTRAINT_TYPE = 'FOREIGN KEY' LEFT JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE fk_ccu ON fk_ccu.CONSTRAINT_NAME = fk_tc.CONSTRAINT_NAME 通常这会在几秒钟内运行,但是在一台运行SQL Server […]