spark-reviews mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From GitBox <>
Subject [GitHub] [spark] maropu opened a new pull request #25707: [SPARK-28587][SQL] Explicitly cast JDBC partition string literals to timestamp/date
Date Fri, 06 Sep 2019 01:59:32 GMT
maropu opened a new pull request #25707: [SPARK-28587][SQL] Explicitly cast JDBC partition
string literals to timestamp/date
   Thanks for sending a pull request!  Here are some tips for you:
     1. If this is your first time, please read our contributor guidelines:
     2. Ensure you have added or run the appropriate tests for your PR:
     3. If the PR is unfinished, add '[WIP]' in your PR title, e.g., '[WIP][SPARK-XXXX] Your
PR title ...'.
     4. Be sure to keep the PR description updated to reflect all changes.
     5. Please write your PR title to summarize what this PR proposes.
     6. If possible, provide a concise example to reproduce the issue for a faster review.
   ### What changes were proposed in this pull request?
   Please clarify what changes you are proposing. The purpose of this section is to outline
the changes and how this PR fixes the issue. 
   If possible, please consider writing useful notes for better and faster reviews in your
PR. See the examples below.
     1. If you refactor some codes with changing classes, showing the class hierarchy will
help reviewers.
     2. If you fix some SQL features, you can provide some references of other DBMSes.
     3. If there is design documentation, please add the link.
     4. If there is a discussion in the mailing list, please add the link.
   This pr proposes to add explicit casts for generated JDBC partition string literals. In
the current master, that logic depends on implicit casts of datasource DBMSs. For example;
   // This assumes we have a relation testdb(t timestamp) in PostgreSQL
   scala> val df ="jdbc")
     .option("url", "jdbc:postgresql...")
     .option("dbtable", "testdb")
     .option("partitionColumn", "t")
     .option("lowerBound", "1972-07-04 03:30:00")
     .option("upperBound", "1972-07-27 14:11:05")
     .option("numPartitions", 2)
   The query above generates  `"t" < '1972-07-15 20:50:32.5' or "t" is null"` and `"t"
>= '1972-07-15 20:50:32.5'` internally for where clauses. Since `t` is timestamp, the clauses
depend on implicit casts of PostgreSQL. The current one looks ok in most databases, but I
believe explicit casts are more reasonable.
   ### Why are the changes needed?
   Please clarify why the changes are needed. For instance,
     1. If you propose a new API, clarify the use case for a new API.
     2. If you fix a bug, you can clarify why it is a bug.
   To support JDBC partitioning broadly.
   ### Does this PR introduce any user-facing change?
   If yes, please clarify the previous behavior and the change this PR proposes - provide
the console output, description and/or an example to show the behavior difference if possible.
   If no, write 'No'.
   ### How was this patch tested?
   If tests were added, say they were added here. Please make sure to add some test cases
that check the changes thoroughly including negative and positive cases if possible.
   If it was tested in a way different from regular unit tests, please clarify how you tested
step by step, ideally copy and paste-able, so that other reviewers can test and check, and
descendants can verify in the future.
   If tests were not added, please describe why they were not added and/or why it was difficult
to add.
   Existing tests.

This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:

With regards,
Apache Git Services

To unsubscribe, e-mail:
For additional commands, e-mail:

View raw message