Re: [HACKERS] path toward faster partition pruning

David Rowley <david.rowley@2ndquadrant.com>

From: David Rowley <david.rowley@2ndquadrant.com>

To: Alvaro Herrera <alvherre@alvh.no-ip.org>

Cc: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Jesper Pedersen <jesper.pedersen@redhat.com>, Robert Haas <robertmhaas@gmail.com>, Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>, Amit Langote <amitlangote09@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Beena Emerson <memissemerson@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>

Date: 2018-04-06T00:02:11Z

Lists: pgsql-hackers

On 6 April 2018 at 10:35, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> I changed a lot of code also, but cosmetic changes only.
>
> I'll clean this up a bit more now, and try to commit shortly (or early
> tomorrow); wanted to share current status now in case I have to rush
> out.

I made a complete pass over the patch you sent. I only noted down the
following few things:

1.

+ * off < 0, meaning the look-up value is smaller that all bounds,

that -> than

2. I guess this will be removed before commit.

+#if 0
<large section of comments>
+#endif

3. This comment seems like a strange thing to write just before
testing if the clause matches the partition key.

+ /* Clause does not match this partition key. */
+ if (equal(leftop, partkey))
+ *rightop = not_clause((Node *) clause)
+ ? (Expr *) makeBoolConst(false, false)
+ : (Expr *) makeBoolConst(true, false);

4. Comment needs removed.

+ * has_default_part - Whether the table has a default partition

The only other thing I noted on this pass is that we could get rid of:

+ /* go check the next clause. */
+ if (unsupported_clause)
+ break;

and just "continue" instead of "break" in all cases apart from case
PARTCLAUSE_UNSUPPORTED:

it would save a few lines and a single condition. What's there works,
but thought this might be better...

-- 
 David Rowley                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

Commits

Fix assorted partition pruning bugs
- d758d9702e2f 11.0 landed
Make gen_partprune_steps static
- d1e2cac5ff7e 11.0 landed
Remove useless 'default' clause
- c775fb9e18ac 11.0 landed
Reorganize partitioning code
- da6f3e45ddb6 11.0 landed
Use custom hash opclass for hash partition pruning
- fafec4cce814 11.0 landed
Blindly attempt to fix sepgsql tests broken due to 9fdb675fc5.
- 4f813c7203e0 11.0 landed
Attempt to fix endianess issues in new hash partition test.
- 40e42e1024c5 11.0 landed
Faster partition pruning
- 9fdb675fc5d2 11.0 landed
For partitionwise join, match on partcollation, not parttypcoll.
- 2af28e603319 11.0 landed
Revise API for partition bound search functions.
- f724022d0ae0 11.0 landed
Revise API for partition_rbound_cmp/partition_rbound_datum_cmp.
- b0229235564f 11.0 landed
Fix possible crash in partition-wise join.
- f069c91a5793 11.0 cited
Refactor code for partition bound searching
- 9aef173163ae 11.0 landed
New C function: bms_add_range
- 84940644de93 11.0 landed
Add extensive tests for partition pruning.
- 8d4e70a63bf8 11.0 landed
Add null test to partition constraint for default range partitions.
- 7b88d63a9122 11.0 cited
Remove BufFile's isTemp flag.
- 11e264517dff 11.0 cited
Make OWNER TO subcommand mention consistent
- bf54c0f05c0a 11.0 cited
Fix index matching for operators with mixed collatable/noncollatable inputs.
- cb37c291060d 9.2.0 cited