how to get the height of index tree?
what's the base of log*a*(*n*) function ? is that base a=16? or something
else? how to know this base ?
2010/10/22 sunpeng <bluevaley@gmail.com>
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Hi, how to get the height of R* or B tree of created index ?
On 10/22/10 11:50 AM, sunpeng wrote:
what's the base of log_/a/ (/n/) function ? is that base a=16? or
something else? how to know this base ?2010/10/22 sunpeng <bluevaley@gmail.com <mailto:bluevaley@gmail.com>>
Hi, how to get the height of R* or B tree of created index ?
it would be based on how many index values plus overhead fits in each 8K
block. highly variable if the field being indexed is TEXT or VARCHAR
or similar.
John R Pierce <pierce@hogranch.com> writes:
2010/10/22 sunpeng <bluevaley@gmail.com <mailto:bluevaley@gmail.com>>
Hi, how to get the height of R* or B tree of created index ?
You could use Gevel for GiST and GIN:
http://www.sai.msu.su/~megera/wiki/Gevel
Don't know if something similar exists for btree, but I guess it would
be very useful.
Regards,
--
Dimitri Fontaine
http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support