Author Archives: user

Khóa học miễn phí PostgreSQL – Locks nhận dự án làm có lương

PostgreSQL – LOCKS Locks or Exclusive Locks or Write Locks prevent users from modifying a row or an entire table. Rows modified by UPDATE and DELETE are then exclusively locked automatically for the duration of the transaction. This prevents other users from changing the row until the transaction is either committed or rolled back. The […]

Khóa học miễn phí PostgreSQL – Views nhận dự án làm có lương

PostgreSQL – VIEWS Views are pseudo-tables. That is, they are not real tables; nevertheless appear as ordinary tables to SELECT. A view can represent a subset of a real table, selecting certain columns or certain rows from an ordinary table. A view can even represent joined tables. Because views are assigned separate permissions, you can […]