MDEV-38072 Optimizer choosing the wrong plan#4758
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mariadb-RexJohnston wants to merge 1 commit into10.11from
Open
MDEV-38072 Optimizer choosing the wrong plan#4758mariadb-RexJohnston wants to merge 1 commit into10.11from
mariadb-RexJohnston wants to merge 1 commit into10.11from
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Under instances where an multiple indexes might be chosen to satify an order by clause with a small limit, the optimizer will choose the shorter index, ignoring the fact that neither the best so far, nor the currently evaluated index are covering. If no index is yet covering, we need to continue to choose the index yeilding the smallest estimated #records for this partial join.
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Under instances where an multiple indexes might be chosen to satify an order by clause with a small limit, the optimizer will choose the shorter index, ignoring the fact that neither the best so far, nor the currently evaluated index are covering. If no index is yet covering, we need to continue to choose the index yeilding the smallest estimated #records for this partial join.