Editing Two-phase locking (section)

===Strict two-phase locking===
To comply with the strict two-phase locking (S2PL) protocol, a transaction needs to comply with 2PL, and release its ''write (exclusive)'' locks only after the transaction has ended (i.e., either ''committed'' or ''aborted''). On the other hand, ''read (shared)'' locks are released regularly during the shrinking phase. 

Unlike 2PL, S2PL provides [[database transaction schedule#Strict|strictness]] (a special case of cascade-less recoverability). This protocol is not appropriate in [[B-tree|B-trees]] because it causes Bottleneck (while B-trees always starts searching from the parent root). {{Citation needed|reason=This claim that S2PL is not appropriate for B-tree is not supported with citation in the edit. From knowledge, S2PL does not affect how storage / B-tree is being handled. |date=November 2016}}