Availability:
:- use_module(library(semweb/rdf_db)).
- hash(+Hash, +Parameter, +Value)
- Set properties for a triple index. Hash is one of
s
,p
,sp
,o
,po
,spo
,g
,sg
orpg
. Parameter is one of:- size
- Value defines the number of entries in the hash-table.
Value is rounded down to a power of 2. After setting
the size explicitly, auto-sizing for this table is disabled. Setting the
size smaller than the current size results in a
permission_error
exception. - average_chain_len
- Set maximum average collision number for the hash.
- optimize_threshold
- Related to resizing hash-tables. If 0, all triples are moved to the new size by the garbage collector. If more then zero, those of the last Value resize steps remain at their current location. Leaving cells at their current location reduces memory fragmentation and slows down access.