Horton

Re: TupleTableSlot abstraction

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Amit Khandekar <amitdkhan.pg@gmail.com>
Cc: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, Robert Haas <robertmhaas@gmail.com>, Haribabu Kommi <kommi.haribabu@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Amit Kapila <amit.kapila16@gmail.com>
Date: 2018-09-25T23:45:09Z
Lists: pgsql-hackers 
Hi,

On 2018-09-04 18:35:34 +0530, Amit Khandekar wrote:
> Subject: [PATCH 05/14] Use tts_flags instead of previous bool members
> 
> Pack the boolean members in TupleTableSlot into a 16 bit tts_flags.
> This reduces the size of TupleTableSlot since each bool member takes
> at least a byte on the platforms where bool is defined as a char.
> 
> Ashutosh Bapat and Andres Freund

> +
> +/* true = slot is empty */
> +#define			TTS_ISEMPTY			(1 << 1)
> +#define IS_TTS_EMPTY(slot)	((slot)->tts_flags & TTS_ISEMPTY)
> +#define SET_TTS_EMPTY(slot) ((slot)->tts_flags |= TTS_ISEMPTY)
> +#define RESET_TTS_EMPTY(slot) ((slot)->tts_flags &= ~TTS_ISEMPTY)

The flag stuff is the right way, but I'm a bit dubious about the
accessor functions.  I can see open-coding the accesses, using the
macros, or potentially going towards using bitfields.

Any comments?

- Andres

Commits

  1. Fix memory leak when inserting tuple at relation creation for CTAS

  2. Build HashState's hashkeys expression with the correct parent.

  3. Move TupleTableSlots boolean member into one flag variable.

  4. Move generic slot support functions from heaptuple.c into execTuples.c.

  5. Remove absolete function TupleDescGetSlot().

  6. Remove function list from prologue of execTuples.c.

  7. Split ExecStoreTuple into ExecStoreHeapTuple and ExecStoreBufferHeapTuple.

  8. Change TupleTableSlot->tts_nvalid to type AttrNumber.

  9. Deduplicate code between slot_getallattrs() and slot_getsomeattrs().

  10. Mention ownership requirements for REFRESH MATERIALIZED VIEW in docs

  11. Spell "partitionwise" consistently.

  12. Fix WHERE CURRENT OF when the referenced cursor uses an index-only scan.