Raymond Raymond <[EMAIL PROTECTED]> writes: > I have a question needs to be confirmed. Anyone can help me? > > In checkpoint, derby checks from the last cached item in the > holder array to the first one(ref: > org.apache.derby.impl.services.cache.Clock.java) > to find dirty pages and write them out. > A cache page, which is clean before checkpoint starts and is updated > after checkpoint starts, will have a chance to be written out by the > current checkpoint process. Am I right? > For instance, let's assume derby keeps 1000 cache pages. When > checkpoint starts, it checks from the 1000th cache page to the > first one. When it goes to check the 800th cache page, the 700th > cache page is updated. The 700th cache page will be checked later > and written out as a dirty page( assume it is valid). If the 900th cache > page is updated when the 800th cache page is checked. The 900th > cache page will not be written out by the current checkpoint process. > Am I right?
Yes, your description of the checkpoint process is correct. -- Knut Anders
