重建索引->更新统计信息？

Question

如果在维护计划中运行重建索引任务，是否必须使用update任务更新统计信息？

Answer 1

是

列统计信息没有重新生成，只有索引统计信息。

--random data
CREATE TABLE dbo.foo (bar int PRIMARY KEY, humbug char(2000))
INSERT dbo.foo (bar, humbug) VALUES (1, 'aaa')
INSERT dbo.foo (bar, humbug) VALUES (2, 'bbb')
INSERT dbo.foo (bar, humbug) VALUES (3, 'ccc')
INSERT dbo.foo (bar, humbug) VALUES (4, 'aaa')
INSERT dbo.foo (bar, humbug) VALUES (5, 'bbb')
INSERT dbo.foo (bar, humbug) VALUES (6, 'ccc')
INSERT dbo.foo (bar, humbug) VALUES (7, 'ccc')
INSERT dbo.foo (bar, humbug) VALUES (8, 'ccc')
INSERT dbo.foo (bar, humbug) VALUES (9, 'ccc')
INSERT dbo.foo (bar, humbug) VALUES (10, 'cc')

INSERT dbo.foo SELECT bar+10, humbug FROM dbo.foo

--generate index stats + column stats
SELECT * FROM foo WHERE bar = 12
SELECT * FROM foo WHERE humbug = 'bbb'

--created date
SELECT
    OBJECT_SCHEMA_NAME([id]) + '.' + OBJECT_NAME([id]),
    NAME,
    STATS_DATE ([id], indid)
FROM
    dbo.sysindexes
WHERE
    OBJECT_NAME([id]) = 'foo'
ORDER BY
    STATS_DATE ([id], indid)  DESC

--Relax, have a coffee

--rebuild
ALTER INDEX ALL ON dbo.foo REBUILD WITH (FILLFACTOR = 90)

--check again
SELECT
    OBJECT_SCHEMA_NAME([id]) + '.' + OBJECT_NAME([id]),
    NAME,
    STATS_DATE ([id], indid)
FROM
    dbo.sysindexes
WHERE
    OBJECT_NAME([id]) = 'foo'
ORDER BY
    STATS_DATE ([id], indid)  DESC

--only index stats were updated

Answer 2

不是的。重建索引将“免费”生成新的统计数据。