Hi Joe,

> Thank you. That sped it up. It's taking 69 seconds to insert 1M records
> (pool "foo.db")
> (class +Invoice +Entity)
> (rel id (+Key +Number))
> (zero N)
> (bench (do 1000000 (new (db: +Invoice) '(+Invoice) 'id (inc 'N)) ))
> (commit)

You can further speed it up if you distribute objects and indices across
separate files. For the above example:

   (class +Invoice +Entity)
   (rel id (+Key +Number))

      (3 )                    # First file, 512 byte blocks
      (2 +Invoice)            # Second file, 256 byte blocks
      (4 (+Invoice id)) )     # Third file, 1024 byte blocks

This puts the '+Invoice' objects into the second file (with a block size
of 256), and the 'id' index into the third (with a block size of 1024).

The first file (with a block size of 512) is not specified to hold any
entities here, so it contains only the administrative data (root and
base objects).

Then you must pass a directory (instead of a file name) and the database
size specifications to 'pool':

   (pool "foo.db/" *Dbs)

If you have really large indexes (more than, say, 10 or 100 million
entries), the you might experiment with an even larger block size (e.g.
6, giving 4096 byte blocks). In my experience performance goes down
again if you use too large block sizes.

> I can work with that. Now I am testing out queries.
> ? (bench (iter (tree 'id '+Invoice) '((This) (inc 'Z (: id) )) )))
> 11.822 sec
> ? (bench (scan (tree 'id '+Invoice) '((Val Key) (inc 'Z Val )) )))
> 4.430 sec
> It makes sense that scan would be fastest because I can use the index
> directly. Is that likely the fastest query to sum up a number relation?

Yes, it is surely faster than a Pilog query (though less powerful).

The absolutely fastest, though, would be to use 'seq', i.e. avoid
completely to use an index. This can be used occasionally, when
(as in the above case) a file consists mainly of objects of a
single type:

      (for (This (seq (db: +Invoice)) This (seq This))
         (inc 'Z (: id)) ) )

If the file also might contain other objects, use this as the last line:

         (and (isa '+Invoice This) (inc 'Z (: id))

- Alex
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