PDSIZE parameter: Difference between revisions
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==Choosing a PDSIZE== | ==Choosing a PDSIZE== | ||
<p>There are two possible paths you can take in choosing a PDSIZE: | <p>There are two possible paths you can take in choosing a PDSIZE:</p> | ||
<ul> | |||
<li> Have one large block containing many pages. Because name searches | |||
always begin with the first block, this increases the likelihood of finding a | always begin with the first block, this increases the likelihood of finding a | ||
name on the first page read. However, as the pages fill up, Model 204 might | name on the first page read. However, as the pages fill up, Model 204 might | ||
allocate a new block when space still exists on the old block. | allocate a new block when space still exists on the old block.</li> | ||
<li>Have a number of smaller blocks with fewer pages. Although it might take | |||
Model 204 longer to find the procedure name, there is less impact on Table | Model 204 longer to find the procedure name, there is less impact on Table | ||
D when a new block is allocated. | D when a new block is allocated.</li></ul> | ||
When choosing PDSIZE, take into account the percentage of procedure and | <p>When choosing PDSIZE, take into account the percentage of procedure and | ||
alias names known or anticipated when you design the file. The fewer aliases | alias names known or anticipated when you design the file. The fewer aliases | ||
your site uses, the smaller the PDSIZE you can use.</p> | your site uses, the smaller the PDSIZE you can use.</p> | ||
Revision as of 14:48, 14 March 2017
Pages per procedure dictionary section
Summary
- Default value
- 3
- Parameter type
- Tables
- Where set
- During file creation
- Related products
- All
- Introduced
- Model 204 V2.1 or earlier
Description
PDSIZE is the number of contiguous pages in a procedure dictionary "section" or "chunk".
When selecting the number, take into account the percentage of procedure names and aliases known or anticipated when the file is designed. PDSIZE can range from 1 to 255.
Choosing a PDSIZE
There are two possible paths you can take in choosing a PDSIZE:
- Have one large block containing many pages. Because name searches always begin with the first block, this increases the likelihood of finding a name on the first page read. However, as the pages fill up, Model 204 might allocate a new block when space still exists on the old block.
- Have a number of smaller blocks with fewer pages. Although it might take Model 204 longer to find the procedure name, there is less impact on Table D when a new block is allocated.
When choosing PDSIZE, take into account the percentage of procedure and alias names known or anticipated when you design the file. The fewer aliases your site uses, the smaller the PDSIZE you can use.