Horton

Re: Tid scan improvements

Alvaro Herrera <alvherre@2ndquadrant.com>

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From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: David Rowley <david.rowley@2ndquadrant.com>
Cc: Edmund Horner <ejrh00@gmail.com>, PostgreSQL Developers <pgsql-hackers@lists.postgresql.org>
Date: 2018-11-06T03:52:49Z
Lists: pgsql-hackers 
On 2018-Nov-06, David Rowley wrote:

> 14. we pass 'false' to what?
> 
> + * save the tuple and the buffer returned to us by the access methods in
> + * our scan tuple slot and return the slot.  Note: we pass 'false' because
> + * tuples returned by heap_getnext() are pointers onto disk pages and were
> + * not created with palloc() and so should not be pfree()'d.  Note also
> + * that ExecStoreHeapTuple will increment the refcount of the buffer; the
> + * refcount will not be dropped until the tuple table slot is cleared.
>   */

Seems a mistake stemming from 29c94e03c7d0 ...

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Add TID Range Scans to support efficient scanning ranges of TIDs

  2. Improve planner's selectivity estimates for inequalities on CTID.