Properly written queries will cut down on those scans. Consider the query you posted. It can be rewritten like this:

;WITH updater AS (

SELECT TOP(@PRM_BufferSize)

TextExtractionStatus,

NEWTextExtractionStatus = (@PRM_Computer_id + 10000),

Computer_id,

NEWComputer_id = @PRM_Computer_id

FROM dbo.tbl_extr_items b

JOIN tbl_extensions d

ON b.extension_id = d.extension_id

JOIN item_types it

ON b.item_type_id = it.item_type_id

WHERE b.TextExtractionStatus IS NULL

AND collection_surr_id = @PRM_Collection_Surr_id

AND active = 1

AND process_status >= 200

ORDER BY item_idx

)

UPDATE updater SET

TextExtractionStatus = NEWTextExtractionStatus,

Computer_id = NEWComputer_id;

- because item_idx is unique. Here's a little test to show how it works:

DROP TABLE #test; DROP TABLE #Second;

CREATE TABLE #test (item_idx INT IDENTITY(1,1) PRIMARY KEY, TextExtractionStatus INT, Computer_id INT);

INSERT INTO #test (TextExtractionStatus, Computer_id)

VALUES (NULL, 10),(NULL, 10),(NULL, 10),(NULL, 10),(NULL, 10),(NULL, 10),(NULL, 10),(NULL, 10),(NULL, 10),(NULL, 10);

CREATE TABLE #Second (item_idx INT, Something INT)

INSERT INTO #Second (item_idx, Something)

VALUES (1,1),(2,1),(4,1),(5,1),(6,1),(7,1),(8,1),(9,1),(10,1),(11,1);

SELECT * FROM #test;

DECLARE @PRM_BufferSize INT = 3, @PRM_Computer_id INT = 5;

WITH updater AS (

SELECT TOP(@PRM_BufferSize)

TextExtractionStatus,

NEWTextExtractionStatus = (@PRM_Computer_id + 10000),

Computer_id,

NEWComputer_id = @PRM_Computer_id

FROM #test t

INNER JOIN #Second s ON s.item_idx = t.item_idx

)

UPDATE updater SET

TextExtractionStatus = NEWTextExtractionStatus,

Computer_id = NEWComputer_id;

SELECT * FROM #test;