How do you deal with multiple users accessing a mySQL database through php? I've a web based system that allows users to access and edit a database, at present there would only ever be one person using the system but that is about to change and I've no idea how to prevent dirty read/writes.
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2PL - how do i cope with multi users
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ok, I know that, but if I want the system to allow a second user to have say only read permissions if the entry is currently in use?
Do I have to lock the whole table (and any related tables) or can i simply lock a row and it's related data?
Do I have to lock the whole table (and any related tables) or can i simply lock a row and it's related data?
That all depends on what table types you are using, and how much overhead you are willing to use. From what I know there are three types of locks:
Table Lock: least overhead (MyISAM, Heap, Merge storage engines)
Page Lock: slightly more overhead (BDB storage engine [uses 8-KB pages])
Row Lock: most overhead (available in InnoDB storage engine)
Hope hope this helps,
Itshim
Table Lock: least overhead (MyISAM, Heap, Merge storage engines)
Page Lock: slightly more overhead (BDB storage engine [uses 8-KB pages])
Row Lock: most overhead (available in InnoDB storage engine)
Hope hope this helps,
Itshim
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