Changes between Version 1 and Version 2 of rfc28_sqlfunc


Ignore:
Timestamp:
Jul 19, 2010, 7:14:28 AM (14 years ago)
Author:
warmerdam
Comment:

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  • rfc28_sqlfunc

    v1 v2  
    2828 * Math: +, -, *, /, **
    2929 * String: CONCAT
    30  
     30
     31== Special Notes ==
     32
     33The existing CAST operator will likely be reworked as a regular function.  This might also imply it can work on the WHERE clause side.
     34
     35The MAX, MIN, AVG, SUM and COUNT operators will not be handled by the expression evaluator.  Their implementation will remain a
     36special case for summarized results.
     37
    3138== Compatability Implications ==
    3239
    3340There are no anticipated backward compatability problems.  For the most part the change results in some OGR SQL statements to work that would previously have generated an error.
     41
     42== Performance Implications ==
     43
     44I am hopeful that the evaluation speed will not be significantly different for simple selections, but each output field will need to be evaluated as an expression (with presumably one value-from-field node).
     45
    3446
    3547== Implementation Plan ==