Alex Behm has posted comments on this change.

Change subject: IMPALA-2328 Parquet scan should use min/max stats
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Patch Set 1:

Thanks for your fast response and consideration.
Your comment makes sense. In order to use the min/max stats in as many 
situations as possible, it seems we need a more general solution. How about 
slightly changing my suggestion to do the following:

In the Impala FE:
1. Use the existing scan tuple for materializing the min stats. Create a new 
tuple identical to the scan tuple for the max stats.
We evaluate predicates against a row that consists of those two tuples.

2. Analyze the scan predicates and generate a list of minMaxConjuncts that are 
evaluated against that min/max row.

In the Impala BE:
3. During the Parquet scan, generate the min/max row, populate the min/max 
tuples and evaluate the list of minMaxConjuncts against that row.

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Gerrit-MessageType: comment
Gerrit-Change-Id: I91de1f4d0fb2a982d06cd344e41901e3bf3c2cea
Gerrit-PatchSet: 1
Gerrit-Project: Impala
Gerrit-Branch: cdh5-trunk
Gerrit-Owner: Jian Wu <[email protected]>
Gerrit-Reviewer: Alex Behm <[email protected]>
Gerrit-Reviewer: Jian Wu <[email protected]>
Gerrit-Reviewer: Michael Ho <[email protected]>
Gerrit-Reviewer: Mostafa Mokhtar <[email protected]>
Gerrit-Reviewer: Tim Armstrong <[email protected]>
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