tsearch2 's access method?
the basic structures to implement the index is :
1.B- tree or the alike.
2.hash structures
So the question is arise:In the tsearch2 model, I thought the general access method is GiST tree, a tree this like B- tree.
But when I saw the crc32_sz() function to hash the tsvector type, the index implementation again turns to be a hash list,
which is the right? hash structures or tree like B tree to implment the index?
沈一枫 wrote:
the basic structures to implement the index is :
1.B- tree or the alike.
2.hash structures
Not only. R-tree, SS-tree, kd-tree, RD-tree etc
So the question is arise:In the tsearch2 model, I thought the general
access method is GiST tree, a tree this like B- tree.But when I saw the crc32_sz() function to hash the tsvector type, the
index implementation again turns to be a hash list,which is the right? hash structures or tree like B tree to implment the
index?
None of them. Tsearch2 use signature tree, which is very close to RD-tree.
GiST (its realisation in pgsql) can store tree likes to R-tree or B-tree (with
some limitations, such as now pgsql's GiST doesn't support order).
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Teodor Sigaev E-mail: teodor@sigaev.ru
WWW: http://www.sigaev.ru/