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Saty · Beginner Joined: 22 Jul 2004 Posts: 1 Topics: 1

SEARCH ALL performs binary search whereas SEARCH performs a linear search in tables. SEARCH ALL is therefore more efficient than SEARCH esp for long tables.

However, the linear search performed by SEARCH can also be accomplished by browsing through an array by varying the subscript. Is the use of SEARCH more efficient than browsing through an array? Is so, why ecaxtly is it more efficient?

kolusu · Posted: Thu Jul 22, 2004 4:19 am Post subject:

saty,

Performance wise there is no difference between COBOL linear search and PERFORM UNTIL. When excueted both of them perform alike.

On the other hand there is a difference between a linear search(SEARCH) and binary search (SEARCH ALL).

Hope this helps...

Cheers

Kolusu
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dhruv · Beginner Joined: 01 Jun 2004 Posts: 10 Topics: 1

The following need to considered when deciding between a linear SEARCH vs PERFORM

SEARCH uses index Specified in the INDEXED BY CLAUSE.

Also, linear SEARCH on a table using a OCCURS DEPENDING ON clause, can come out of the search faster.

kolusu · Posted: Thu Jul 22, 2004 4:32 am Post subject:

dhruv · Beginner Joined: 01 Jun 2004 Posts: 10 Topics: 1

Lets say you a table with 100 elements.

But only the first 30 elements have been populated. IF the ODOvariable is 30, then the SEARCH will come out after scanning through the first 30 elements, rather than searcing all 100 elements.

Hope its clear

Thanks

kolusu · Posted: Thu Jul 22, 2004 4:40 am Post subject:

dhruv · Beginner Joined: 01 Jun 2004 Posts: 10 Topics: 1

If you use a limiting factor (equivalent of the ODO) in the PERFORM VARYING statement, in conjunction with an indexed variable(not a working storage variable), then i suppose the PERFORM VARYING might come close to the SEARCH performance wise, although, even for big tables, there is very little difference to chose from the 2.

Thanks