I inherited this hellish query designed for pagination in SQL Server.
It's only getting 25 records, but according to SQL Profiler, it does 8091 reads, 208 writes and takes 74 milliseconds. Would prefer it to be a bit faster. There is an index on the ORDER BY column deployDate
.
Anyone have any ideas on how to optimise it?
SELECT TOP 25
textObjectPK, textObjectID, title, articleCredit, mediaCredit,
commentingAllowed,deployDate,
container, mediaID, mediaAlign, fileName AS fileName, fileName_wide AS fileName_wide,
width AS width, height AS height,title AS mediaTitle, extension AS extension,
embedCode AS embedCode, jsArgs as jsArgs, description as description, commentThreadID,
totalRows = Count(*) OVER()
FROM
(SELECT
ROW_NUMBER() OVER (ORDER BY textObjects.deployDate DESC) AS RowNumber,
textObjects.textObjectPK, textObjects.textObjectID, textObjects.title,
textObjects.commentingAllowed, textObjects.credit AS articleCredit,
textObjects.deployDate,
containers.container, containers.mediaID, containers.mediaAlign,
media.fileName AS fileName, media.fileName_wide AS fileName_wide,
media.width AS width, media.height AS height, media.credit AS mediaCredit,
media.title AS mediaTitle, media.extension AS extension,
mediaTypes.embedCode AS embedCode, media.jsArgs as jsArgs,
media.description as description, commentThreadID,
TotalRows = COUNT(*) OVER ()
FROM textObjects WITH (NOLOCK)
INNER JOIN containers WITH (NOLOCK)
ON containers.textObjectPK = textObjects.textObjectPK
AND (containers.containerOrder = 0 or containers.containerOrder = 1)
INNER JOIN LUTextObjectTextObjectGroup tog WITH (NOLOCK)
ON textObjects.textObjectPK = tog.textObjectPK
AND tog.textObjectGroupID in (3)
LEFT OUTER JOIN media WITH (NOLOCK)
ON containers.mediaID = media.mediaID
LEFT OUTER JOIN mediaTypes WITH (NOLOCK)
ON media.mediaTypeID = mediaTypes.mediaTypeID
WHERE (((version = 1)
AND (textObjects.textObjectTypeID in (6))
AND (DATEDIFF(minute, deployDate, GETDATE()) >= 0)
AND (DATEDIFF(minute, expireDate, GETDATE()) <= 0))
OR ( (version = 1) AND (textObjects.textObjectTypeID in (6))
AND (DATEDIFF(minute, deployDate, GETDATE()) >= 0)
AND (expireDate IS NULL)))
AND deployEnglish = 1
) tmpInlineView
WHERE RowNumber >= 51
ORDER BY deployDate DESC
I am in a similar position to with the same sort of queries. Here are some tips:
Also, rewrite the two LEFT OUTER JOINs
like this:
LEFT OUTER JOIN
(
media WITH (NOLOCK)
LEFT OUTER JOIN mediaTypes WITH (NOLOCK)
ON media.mediaTypeID = mediaTypes.mediaTypeID
)
ON containers.mediaID = media.mediaID
which should make the query optimizer behave a little better.
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