Re: Row and Page locking - time difference

Vijay R. Anisetti wrote: > > Bill Glidden wrote: > > > > davin_harvey@dsti.co.uk wrote: > > : Hi everybody, > > : =20 > > : Does anyone know if there is a difference in the time it > takes to=20 > > : place a row lock rather than a page lock? > > : =20 > > : Ta > > : Davin > > > > no difference that I can think of. > > Though there might be a difference between the two, it will be > negligible > should play no importance in the decision making. > > My theory is that a Page lock is quicker as there is a defined no. of > bytes > to lock all the time. Whereas for a row lock it requires to know the > no. > of > bytes to lock and task of calculating the rowsize is compounded if it > has any > variable columns in size (varchar). Mark D. Stock Wrote: >I think you're confusing row lock with byte lock. The latter does need >to know the number of characters that changed. I don't think I'm. As I understand there is no difference between the two, OS needs to know from what offset to what offset of the disk needs to locked, getting the info. from the disk, either thru a file descriptor/id or a direct physical address. Direct physical address (i assume) is the method used by Informix-online for rawdisk handling. Irrespective of whether it is rawdisk or cooked file, the basic difference the row (variable) and page (relatively constant) will result in the difference in time it takes to lock, as I explained before. Anybody with a difference of opinion or more input? -- \\\\|// Vijay R. Anisetti |6 6| -------------------oooO--U--Oooo---------------------------- oooO Oooo ( ) ( ) Watching NT closely ---------------\\( -- )/------------------------------------- \\) (/