So lets say I am trying to delete rows from the BDNotes table structured as
below
R>list bdnotes
Table: bdnotes No Lock(s)
No. Column Name Attributes
--- ------------------ ------------------------------
1 noten Type : INTEGER AUTONUMBER
Index : SINGLE-COLUMN
2 POn Type : TEXT 12
Index : SINGLE-COLUMN
3 time_stamp Type : DATETIME
Index : SINGLE-COLUMN
4 notes Type : NOTE 228
5 BD_U_P Type : INTEGER
Index : SINGLE-COLUMN
Current number of rows:2277914
Next table is a single column table projected from master based on specific
criteria.
1 POn Type : TEXT 12
Index : SINGLE-COLUMN
Command used for deletion is: del rows from bdnotes where pon in (sel pon
from deltable)
How does this look. It runs slow. The process is deleting 365,000 records or
so.
-----Original Message-----
From: A. Razzak Memon [mailto:[EMAIL PROTECTED]
Sent: Tuesday, April 26, 2005 4:49 PM
To: [email protected]
Subject: [RBASE-L] - Re: Deleting row question
At 05:05 PM 4/26/2005, Steve Breen wrote:
>How would you speed up the process?
In a WHERE clause, R:BASE uses only one index (except when
joining tables). By knowing which indexed column the R:BASE
optimizer use in a WHERE clause, you can structure your
conditions so that the optimizer uses the most unique (and
thus most helpful) index. This is where knowing your data
helps you to modify command(s) and gain speed.
On the other hand, if you are LOADing many rows of data at
a time, it is considerably faster to DROP the indexes, load
the data, and then rebuild the indexes. It is faster for
R:BASE to build the indexes in one chunk rather than updating
them as each row is loaded. You can optimize this by using
CREATE INDEX command.
Tip:
Always RELOAD database after deleting lots of rows.
Hope that helps!
Very Best R:egards,
Razzak.
