NoLocks // 1.9.8b10 adoption of record locks. Feedback

[Ruslan Zasukhin]

on 7/4/03 18:20, erne at ernestogiannotta at tiscalinet.it wrote:

>> Am I understanding correctly above that the second request for 9
>> records is Read Only? Hmmm, that could really tie things up. One record
>> in Write mode could hold up reading loads of records. What does an
>> application, or user, do while waiting for records?!
>> 
> 
> seen from the other side, if one cursor is used for browse purposes in read
> only lock mode it can prevent the writing of a single record for hours!
> 
> this way the use of cursors will be reduced to a take-the-data-and-run mode
> i.e. you MUST release the cursor ASAP to avoid the entire system to be clogged
> up

YES !!!

If you develop something multi-user you need follow rule

    make transactions AS SHORT AS POSSIBLE in time,
    and select as FEW records as possible. In ideal just one.


Big DBMS do not like query as "SELECT * FROM T"  :-)

Not, that if you work with server and ask for client cursor (which is always
read only) then you get copy of records to you local computer and records
are unlocked. 

Also if you make read only cursor DBMS can decide (or in future we will get
option) create on SERVER side TMP table with result of query, so main table
can be released.


-- 
Best regards,
Ruslan Zasukhin      [ I feel the need...the need for speed ]
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e-mail: ruslan at paradigmasoft.com
web: http://www.paradigmasoft.com

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