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Overview
Comment: | When planning a query using sorting, resolve ties in the solver by selecting loop plans with the smaller unsorted cost. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA3-256: |
f261678c90297f9767040c577796cc1d |
User & Date: | drh 2017-05-22 00:45:15.475 |
Context
2017-05-22
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08:04 | Fix a case where NULL was being passed to memcmp() following an OOM. This is probably not a real problem, as the number-of-bytes parameter was passed 0 in this case, but it was causing a santizer complaint. (check-in: 3ea2bad27e user: dan tags: trunk) | |
00:45 | When planning a query using sorting, resolve ties in the solver by selecting loop plans with the smaller unsorted cost. (check-in: f261678c90 user: drh tags: trunk) | |
00:27 | When planning a query using sorting, resolve ties in the solver by selecting loop plans with the smaller unsorted cost. (check-in: 962531e7c1 user: drh tags: branch-3.8.9) | |
2017-05-19
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22:51 | Prevent a possible NULL pointer dereference in the OP_Found opcode that can follow an OOM error. Problem found by OSS-Fuzz. (check-in: c2de178fe7 user: drh tags: trunk) | |
Changes
Changes to src/where.c.
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3999 4000 4001 4002 4003 4004 4005 | && (rCost>mxCost || (rCost==mxCost && rUnsorted>=mxUnsorted)) ){ /* The current candidate is no better than any of the mxChoice ** paths currently in the best-so-far buffer. So discard ** this candidate as not viable. */ #ifdef WHERETRACE_ENABLED /* 0x4 */ if( sqlite3WhereTrace&0x4 ){ | | | | | | | > > > > | > > > > > > | | | | | | | | | 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 | && (rCost>mxCost || (rCost==mxCost && rUnsorted>=mxUnsorted)) ){ /* The current candidate is no better than any of the mxChoice ** paths currently in the best-so-far buffer. So discard ** this candidate as not viable. */ #ifdef WHERETRACE_ENABLED /* 0x4 */ if( sqlite3WhereTrace&0x4 ){ sqlite3DebugPrintf("Skip %s cost=%-3d,%3d,%3d order=%c\n", wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted, isOrdered>=0 ? isOrdered+'0' : '?'); } #endif continue; } /* If we reach this points it means that the new candidate path ** needs to be added to the set of best-so-far paths. */ if( nTo<mxChoice ){ /* Increase the size of the aTo set by one */ jj = nTo++; }else{ /* New path replaces the prior worst to keep count below mxChoice */ jj = mxI; } pTo = &aTo[jj]; #ifdef WHERETRACE_ENABLED /* 0x4 */ if( sqlite3WhereTrace&0x4 ){ sqlite3DebugPrintf("New %s cost=%-3d,%3d,%3d order=%c\n", wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted, isOrdered>=0 ? isOrdered+'0' : '?'); } #endif }else{ /* Control reaches here if best-so-far path pTo=aTo[jj] covers the ** same set of loops and has the same isOrdered setting as the ** candidate path. Check to see if the candidate should replace ** pTo or if the candidate should be skipped. ** ** The conditional is an expanded vector comparison equivalent to: ** (pTo->rCost,pTo->nRow,pTo->rUnsorted) <= (rCost,nOut,rUnsorted) */ if( pTo->rCost<rCost || (pTo->rCost==rCost && (pTo->nRow<nOut || (pTo->nRow==nOut && pTo->rUnsorted<=rUnsorted) ) ) ){ #ifdef WHERETRACE_ENABLED /* 0x4 */ if( sqlite3WhereTrace&0x4 ){ sqlite3DebugPrintf( "Skip %s cost=%-3d,%3d,%3d order=%c", wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted, isOrdered>=0 ? isOrdered+'0' : '?'); sqlite3DebugPrintf(" vs %s cost=%-3d,%3d,%3d order=%c\n", wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow, pTo->rUnsorted, pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?'); } #endif /* Discard the candidate path from further consideration */ testcase( pTo->rCost==rCost ); continue; } testcase( pTo->rCost==rCost+1 ); /* Control reaches here if the candidate path is better than the ** pTo path. Replace pTo with the candidate. */ #ifdef WHERETRACE_ENABLED /* 0x4 */ if( sqlite3WhereTrace&0x4 ){ sqlite3DebugPrintf( "Update %s cost=%-3d,%3d,%3d order=%c", wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, rUnsorted, isOrdered>=0 ? isOrdered+'0' : '?'); sqlite3DebugPrintf(" was %s cost=%-3d,%3d,%3d order=%c\n", wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow, pTo->rUnsorted, pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?'); } #endif } /* pWLoop is a winner. Add it to the set of best so far */ pTo->maskLoop = pFrom->maskLoop | pWLoop->maskSelf; pTo->revLoop = revMask; pTo->nRow = nOut; |
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