On 29/06/12 02:49, Sarven Capadisli wrote:
On 2012-06-28 20:25, Andy Seaborne wrote:
On 28/06/12 10:11, Sarven Capadisli wrote:
I was wondering if there is a way to rebuild the TDB index from
command-line and have it consequently update the stats file?
There isn't a way to rebuild just one of the indexes from another in the
TDB distribution. Is that you want to do?
tdbstats calculates the stats.
I want to optimize query response times.
I can't get a satisfactory solution with tdbstats because it doesn't let
me optimize for each named graph in the store.
What sort of queries are you asking the store?
I thought rebuilding the indexes might create a new stats file. As I
understand it, the stats file is created after the initial import with
tdbloader, and subsequent imports don't update the stats file.
True - but you just need to rebuild the stats, not the index itself.
The stats file is separate from the index.
I suppose at this point I need to compare the performances between the
stats that's created after importing incrementally (meanwhile initial
import being the largest), and the stats that's based on the union of
graphs.
That's all in context of having the data dumps in N-Triples format where
each dump is assigned a named graph.
Alternatively, I have to switch to using a single dump file in N-Quads,
but I'm thinking that the stats for that would get me at best the same
results as in the union of graphs approach.
Does this line of thinking makes sense: Which state should the TDB
indexes be in such that I get the most preferable stats? Is there even a
need to rebuild the indexes?
No point rebuilding the indexes.
You can write a stats file by hand.
But I think the first step is understand the queries.
Andy
-Sarven
