[Progress Communities] [Progress OpenEdge ABL] Forum Post: RE: How does client-server ABL recover from locked database record?

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gus bjorklund

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> On Oct 10, 2019, at 5:44 PM, dbeavon wrote: > > the most confusing to me was the information in the "_lock" VST When deleting records, first an exclusive lock is acquired if one is not already in effect. then the record is deleted and replaced by a "rowid placeholder". that is done so that no one else can take that rowid until after the deleting transaction has been committed. otherwise if someone else took the rowid, it would be impossible to undo the incomplete transaction. then, after the row is deleted, the exclusive lock in the lock table is removed as it is no longer needed. the rowid placeholder serves as an exclusive lock. thus a loop that deletes many records only uses one entry in the lock table.

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