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Commit8494064

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New C function: bms_add_range
This will be used by pending patches to improve partition pruning.Amit Langote and Kyotaro Horiguchi, per a suggestion from DavidRowley. Review and testing of the larger patch set of which this is apart by Ashutosh Bapat, David Rowley, Dilip Kumar, Jesper Pedersen,Rajkumar Raghuwanshi, Beena Emerson, Amul Sul, and Kyotaro Horiguchi.Discussion:http://postgr.es/m/098b9c71-1915-1a2a-8d52-1a7a50ce79e8@lab.ntt.co.jp
1 parent8d4e70a commit8494064

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2 files changed

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‎src/backend/nodes/bitmapset.c

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Original file line numberDiff line numberDiff line change
@@ -784,6 +784,78 @@ bms_add_members(Bitmapset *a, const Bitmapset *b)
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returnresult;
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}
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/*
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* bms_add_range
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*Add members in the range of 'lower' to 'upper' to the set.
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*
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* Note this could also be done by calling bms_add_member in a loop, however,
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* using this function will be faster when the range is large as we work with
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* at the bitmapword level rather than at bit level.
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*/
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Bitmapset*
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bms_add_range(Bitmapset*a,intlower,intupper)
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{
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intlwordnum,
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lbitnum,
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uwordnum,
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ushiftbits,
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wordnum;
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if (lower<0||upper<0)
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elog(ERROR,"negative bitmapset member not allowed");
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if (lower>upper)
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elog(ERROR,"lower range must not be above upper range");
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uwordnum=WORDNUM(upper);
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if (a==NULL)
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{
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a= (Bitmapset*)palloc0(BITMAPSET_SIZE(uwordnum+1));
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a->nwords=uwordnum+1;
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}
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/* ensure we have enough words to store the upper bit */
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elseif (uwordnum >=a->nwords)
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{
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intoldnwords=a->nwords;
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inti;
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a= (Bitmapset*)repalloc(a,BITMAPSET_SIZE(uwordnum+1));
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a->nwords=uwordnum+1;
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/* zero out the enlarged portion */
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for (i=oldnwords;i<a->nwords;i++)
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a->words[i]=0;
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}
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wordnum=lwordnum=WORDNUM(lower);
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lbitnum=BITNUM(lower);
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ushiftbits=BITS_PER_BITMAPWORD- (BITNUM(upper)+1);
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/*
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* Special case when lwordnum is the same as uwordnum we must perform the
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* upper and lower masking on the word.
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*/
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if (lwordnum==uwordnum)
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{
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a->words[lwordnum] |= ~(bitmapword) (((bitmapword)1 <<lbitnum)-1)
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& (~(bitmapword)0) >>ushiftbits;
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}
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else
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{
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/* turn on lbitnum and all bits left of it */
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a->words[wordnum++] |= ~(bitmapword) (((bitmapword)1 <<lbitnum)-1);
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/* turn on all bits for any intermediate words */
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while (wordnum<uwordnum)
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a->words[wordnum++]= ~(bitmapword)0;
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/* turn on upper's bit and all bits right of it. */
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a->words[uwordnum] |= (~(bitmapword)0) >>ushiftbits;
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}
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returna;
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}
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/*
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* bms_int_members - like bms_intersect, but left input is recycled
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*/

‎src/include/nodes/bitmapset.h

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -90,6 +90,7 @@ extern bool bms_is_empty(const Bitmapset *a);
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externBitmapset*bms_add_member(Bitmapset*a,intx);
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externBitmapset*bms_del_member(Bitmapset*a,intx);
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externBitmapset*bms_add_members(Bitmapset*a,constBitmapset*b);
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externBitmapset*bms_add_range(Bitmapset*a,intlower,intupper);
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externBitmapset*bms_int_members(Bitmapset*a,constBitmapset*b);
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externBitmapset*bms_del_members(Bitmapset*a,constBitmapset*b);
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externBitmapset*bms_join(Bitmapset*a,Bitmapset*b);

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