Обсуждение: fulldisjunction - fd: Moved the calculations of whether to use an index

Log Message:
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Moved the calculations of whether to use an index scan to a seperate calculation instead of doing this while
constructingthe query. Also, moved allocation of strings and calculations of strings sizes to after the calculation.
Alsoimproved prediction of query size. 

Modified Files:
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    fd:
        algutils.c (r1.13 -> r1.14)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/fulldisjunction/fd/algutils.c.diff?r1=1.13&r2=1.14)