Sepertinya saya baru saja memperbarui kolom untuk NULL
akan merilis halaman untuk digunakan kembali. Ini demo Very Scottish®, untuk merayakannya hampir jam 5 sore, EST.
USE tempdb;
DROP TABLE IF EXISTS dbo.RobertBurns;
CREATE TABLE dbo.RobertBurns
(
Id INT IDENTITY(1, 1) PRIMARY KEY CLUSTERED,
Scotch VARCHAR(50),
HaggisAddress VARBINARY(MAX)
);
DECLARE @AddressToAVarbinaryHaggis VARBINARY(MAX);
DECLARE @AddressToAHaggis NVARCHAR(MAX) = N'
Good luck to you and your honest, plump face,
Great chieftain of the pudding race!
Above them all you take your place,
gut, stomach-lining, or intestine,
You''re well worth a grace
as long as my arm.
The overloaded serving tray there you fill,
Your buttocks shaped like a distant hilltop,
Your wooden skewer could be used to fix a mill
if need be,
While through your pores your juices drip
like liquid gold.
His knife see the serving-man clean,
And then cut you up with great skill,
Making a trench in your bright, gushing guts
To form a ditch,
And then, 0h! What a glorious sight!
Warm, steaming, and rich!
Then, spoonful after spoonful, they eagerly eat,
The devil will get the last bit, on they go,
Until all their well-stretched stomachs, by-and-by,
are bent like drums,
Then the head of the family, about to burst,
murmurs “Thank the Lord".
Is there a pretentious soul who, over his French ragout,
Or Italian cuisine that would make a pig sick,
Or French stew that would make that same pig ill
with complete and utter disgust,
Looks down with a sneering, scornful attitude,
on such a meal? (as Haggis)
Poor devil! See him over his trash!
As feeble as a withered bullrush,
His skinny leg no thicker than a thin rope,
His fist the size of a nut,
Through a river or field to travel,
Completely unfit!
But look at the healthy, Haggis-fed person!
The trembling earth respects him as a man!
Put a knife in his fist,
He''ll make it work!
And legs, and arms, and heads will come off,
Like the tops of thistle.
You Powers who look after mankind,
And dish out his bill of fare,
Old Scotland wants no watery, wimpy stuff
That splashes about in little wooden bowls!
But, if You will grant her a grateful prayer,
Give her a Haggis!';
INSERT dbo.RobertBurns (Scotch, HaggisAddress )
SELECT TOP 1000
CASE WHEN x.c % 15 = 0 THEN 'Laphroaig'
WHEN x.c % 5 = 0 THEN 'Lagavulin'
WHEN x.c % 3 = 0 THEN 'Port Ellen'
ELSE 'Ardbeg'
END AS Scotch,
CONVERT(VARBINARY(MAX), REPLICATE(@AddressToAHaggis, x.c % 20 + 1))
FROM (
SELECT ROW_NUMBER() OVER (ORDER BY @@ROWCOUNT) AS c
FROM sys.messages AS m
) AS x;
CREATE INDEX ix_novarbinary ON dbo.RobertBurns (Scotch, Id);
CREATE INDEX ix_yesvarbinary ON dbo.RobertBurns (Scotch, Id) INCLUDE (HaggisAddress);
Dengan baris yang dimasukkan, mari kita periksa halaman indeks kami.
SELECT OBJECT_NAME(i.object_id) AS table_name,
i.name AS index_name,
MAX(a.used_pages) AS leaf_me_alone
FROM sys.indexes AS i
JOIN sys.partitions AS p
ON p.object_id = i.object_id
AND p.index_id = i.index_id
JOIN sys.allocation_units AS a
ON a.container_id = p.partition_id
WHERE OBJECT_NAME(i.object_id) = 'RobertBurns'
GROUP BY i.object_id, i.index_id, i.name
ORDER BY OBJECT_NAME(i.object_id), i.index_id;
Setelah dimasukkan, saya mendapatkan ini. Halaman yang sebenarnya dapat bervariasi untuk Anda.
table_name index_name leaf_me_alone
RobertBurns PK__RobertBu__3214EC074BE633A2 5587
RobertBurns ix_novarbinary 10
RobertBurns ix_yesvarbinary 5581
Mari kita NULL
keluar beberapa baris!
UPDATE rb
SET rb.HaggisAddress = NULL
FROM dbo.RobertBurns AS rb
WHERE rb.Id % 15 = 0;
Dan periksa kembali di halaman kami:
table_name index_name leaf_me_alone
RobertBurns PK__RobertBu__3214EC074BE633A2 5300
RobertBurns ix_novarbinary 10
RobertBurns ix_yesvarbinary 5273
Jadi jumlah halaman berkurang. Sabas! Untuk dua indeks yang menyentuh VARBINARY
data kami , mereka kehilangan banyak halaman. Itu berarti mereka kembali beredar untuk digunakan benda lain. Karena saya di tempdb, mereka mungkin akan menelan cukup cepat oleh semua hal-hal sampah yang terjadi di sini.
Sekarang mari kita masukkan kembali beberapa data:
INSERT dbo.RobertBurns (Scotch, HaggisAddress )
SELECT TOP 10 rb.Scotch, rb.HaggisAddress
FROM dbo.RobertBurns AS rb;
Dan memeriksa kembali:
table_name index_name leaf_me_alone
RobertBurns PK__RobertBu__3214EC074BE633A2 5330
RobertBurns ix_novarbinary 11
RobertBurns ix_yesvarbinary 5305
Jumlah halaman sedikit meningkat.
Jadi, sepertinya Anda tidak perlu melakukan sesuatu yang terlalu gila, atau bahkan mengecilkan database Anda untuk mendapatkan ruang kembali. Saya pikir Anda menggabungkan perilaku menjatuhkan kolom dan perlu menjalankan DBCC CLEANTABLE
apa yang sebenarnya Anda lakukan.
Semoga ini membantu!