BSDDB Pack function?

[Robert Roy]

(from Robin's Reference Guide)

ref B-Tree dbs 
 
 Space freed by deleting key/data pairs from the database is never
 reclaimed from the filesystem, although it is reused where possible.
 This means that the btree storage structure is grow-only.  If
 sufficiently many keys are deleted from a tree that shrinking the
 underlying database file is desirable, this can be accomplished by
 creating a new tree from a scan of the existing one.
  

You don't have to export to ascii and re-import. Try something like
this.

from TCS.bsddb import db
d = db.DB()
d.open('test.db', db.DB_BTREE)
e = db.DB()
e.open('test2.db', db.DB_BTREE, db.DB_CREATE)
c=d.cursor()
try:
    while 1:
        key,val = c.next()
        print key,val
        e[key]=val
except db.error, val:
    print 'errror', val
c.close()
e.close()
d.close()




On Tue, 15 Feb 2000 11:06:32 -0500, "Warren Postma"
<embed at geocities.com> wrote:

>> approximately 3 times faster using your bsddb.
>
>Well it finished running in under an hour, whereas the stock python bsddb
>library took over four hours to finish.  However, at the end, when I had
>deleted around 150,000 rows from the table, leaving 25,000 rows, the file
>itself had not "shrunk" at all and was still over 200 mb.  This is okay,
>since it's rare that you'd really want to deallocate the disk space, since
>it's just going to get used again next time you add more records, however a
>"pack" function (like we had for dbf files) would be nice.
>
>Is there one or must I export the file to flat ASCII, and re-create a file
>to pack it down when much data is deleted?
>
>Warren Postma
>
>