Re: Database Locking?!?
This WebDNA talk-list message is from 2000
It keeps the original formatting.
numero = 26114
interpreted = N
texte = Dear Howard - You don't _have_ to do the big search. Create a LastNumber.db with a single column and store your sequential number there. Initially, populate it with highest number in use. Now, do an UPDATE with a nested lookup on the LastNumber.db and increase the sequence number, using that new sequence number to APPEND to the main database. You are always doing a search on a single record database, and the atomic nature of lookup feeding the update will mean that you cannot get a duplicate sequence number.HTHJohn Peacock ____________________Reply Separator____________________ Subject: Database Locking?!? Author:
(WebCatalog Talk) Date: 1/12/00 4:32 PMThis has been discussed before and I'm bringing it up again...Database locking. Let me make a few quick assumptions for my problem to prevent solutions that I can't use: 1. I MUST use my sequential number solution as the record ID. 2. Refer to #1 3. I can't really reduce the size of the database for other reasons.Based on the above assumptions, I do a search on a database in order to determine the next sequential number, and then I append the record with that new ID number, and all it's information (a lot of information).Unfortunately, it seems that this append takes so long (much less than a second, but long enough to cause this problem), if another person hits the page, they TOO will get that same ID since the new one wasn't appended to the database before they hit that page. It's gotten to a point where I actually can get 6 duplicate IDs, and that's just plain bad.My question is, I need to do database locking somehow. If I do my search INSIDE of the append, will that lock access to the database until the append completes, and therefore solve my duplicate ID problem?If not, any other ideas on this (but sticking to the top 3 assumptions)?Thanks. Appreciate any help on this one that I can get.-Howard ------------------------------------------------------------- Brought to you by CommuniGate Pro - The Buzz Word Compliant Messaging Server. To end your Mail problems go to .This message is sent to you because you are subscribed to the mailing list . To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to
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- Re: Database Locking?!? ( 2000)
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Dear Howard - You don't _have_ to do the big search. Create a LastNumber.db with a single column and store your sequential number there. Initially, populate it with highest number in use. Now, do an UPDATE with a nested lookup on the LastNumber.db and increase the sequence number, using that new sequence number to APPEND to the main database. You are always doing a search on a single record database, and the atomic nature of lookup feeding the update will mean that you cannot get a duplicate sequence number.HTHJohn Peacock ____________________Reply Separator____________________ Subject: Database Locking?!? Author: (WebCatalog Talk) Date: 1/12/00 4:32 PMThis has been discussed before and I'm bringing it up again...Database locking. Let me make a few quick assumptions for my problem to prevent solutions that I can't use: 1. I MUST use my sequential number solution as the record ID. 2. Refer to #1 3. I can't really reduce the size of the database for other reasons.Based on the above assumptions, I do a search on a database in order to determine the next sequential number, and then I append the record with that new ID number, and all it's information (a lot of information).Unfortunately, it seems that this append takes so long (much less than a second, but long enough to cause this problem), if another person hits the page, they TOO will get that same ID since the new one wasn't appended to the database before they hit that page. It's gotten to a point where I actually can get 6 duplicate IDs, and that's just plain bad.My question is, I need to do database locking somehow. If I do my search INSIDE of the append, will that lock access to the database until the append completes, and therefore solve my duplicate ID problem?If not, any other ideas on this (but sticking to the top 3 assumptions)?Thanks. Appreciate any help on this one that I can get.-Howard ------------------------------------------------------------- Brought to you by CommuniGate Pro - The Buzz Word Compliant Messaging Server. To end your Mail problems go to .This message is sent to you because you are subscribed to the mailing list . To unsubscribe, E-mail to: To switch to the DIGEST mode, E-mail to
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