Planning

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Planning#

Left Join#

The following optimizes a left join.

  • Pushing selection down on the left

  • Choosing the selection that reduce the left the most to be pushed down.

  • Pushing any cartesian operator up.

  • Create temporary tables from result of selection instead of doing things iteratively.

  • Switch join algorithm (SNLJ, PNLJ, BNLJ)

  • Cascade and push down projections.

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