title: Details of impact of different locking schemes in databases?
body: <p>I'm testing different locking schemes for a big table, more than 4 million rows and expected to grow up to 10 million.</p>
  
  <p>My experience with SyBase:<br/>
  ALLPAGES, extremely slow BCP (in) and update with a field that belongs to the Primary Key.<br/>
  DATAROWS, fast BCP, fast update for fields in the PK, fastest select.<br/>
  DATAPAGES, fastest BCP and update, and faster select than ALLPAGES but not as fast as DATAROWS.<br/></p>
  
  <p>I'm not an expert, but it seems to me that DATAROWS blocks more than DATAPAGES, and I haven't seen any downside with DATAPAGES.</p>
  
  <p>The only point in favor for DATAROWS that I could find was a bit faster performance in selects that use primary key, but DATAPAGES is considerably faster at updates.</p>
  
  <p>Any experiences in practice?<br/>
  How does this locking schemes compare?<br/>
  Pros/Cons of each one?</p>
  
  <p>I tried to read about the theory behind it, but it's not very clear to me.</p>