PostgreSQL TODO List

====================

Current maintainer:Bruce Momjian (pgman@candle.pha.pa.us)

Last updated:Thu Dec 1 17:12:27 EST 2005

Last updated:Thu Dec 1 17:30:23 EST 2005

The most recent version of this document can be viewed at

http://www.postgresql.org/docs/faqs.TODO.html.

Currently indexes do not have enough tuple visibility information

to allow data to be pulled from the index without also accessing

the heap. One way to allow this is to set a bitto index tuples

the heap. One way to allow this is to set a biton index tuples

to indicate if a tuple is currently visible to all transactions

when the first valid heap lookup happens. This bit would have to

be cleared when a heap tuple is expired.

be cleared when a heap tuple is expired. Another idea is to maintain

a bitmap of heap pages where all rows are visible to all backends,

and allow index lookups to reference that bitmap to avoid heap

lookups, perhaps the same bitmap we might add someday to determine

which heap pages need vacuuming.

* Consider automatic caching of queries at various levels:

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<h1><aname="section_1">PostgreSQL TODO List</a></h1>

<p>Current maintainer: Bruce Momjian (<ahref="mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</a>)<br/>

Last updated: Thu Dec 1 17:12:27 EST 2005

Last updated: Thu Dec 1 17:30:23 EST 2005

<p>The most recent version of this document can be viewed at<br/>

<ahref="http://www.postgresql.org/docs/faqs.TODO.html">http://www.postgresql.org/docs/faqs.TODO.html</a>.

</li><li>Allow data to be pulled directly from indexes

<p> Currently indexes do not have enough tuple visibility information

to allow data to be pulled from the index without also accessing

the heap. One way to allow this is to set a bitto index tuples

the heap. One way to allow this is to set a biton index tuples

to indicate if a tuple is currently visible to all transactions

when the first valid heap lookup happens. This bit would have to

be cleared when a heap tuple is expired.

be cleared when a heap tuple is expired. Another idea is to maintain

a bitmap of heap pages where all rows are visible to all backends,

and allow index lookups to reference that bitmap to avoid heap

lookups, perhaps the same bitmap we might add someday to determine

which heap pages need vacuuming.

</li><li>Consider automatic caching of queries at various levels: