- permanent cache flush is switched off. The optimized cache flush
works better if it is a large number of collections that is flushed
together
- the flush size can be configured instead the flush divisor. There is
only one size for all flushes
- collection records that shall be removed during collection transition
(jump from one collection file to another) are now not really removed
but only marked in RAM. add-operations to the collection use these
marked collection spaces
- index bulk write operations are now separated for each file of a kelondroFlex
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@3414 6c8d7289-2bf4-0310-a012-ef5d649a1542
redesign for better IO performance
enhanced database seek-time by avoiding write operations at distant
positions of a database file. until now, a USEDC counter was written
at the head-section of a kelondroRecords database file (which is the
basic data structure of all kelondro database files) to store the
actual number of records that are contained in the database. Now, this
value is computed from the database file size. This is either done
only once at start-time, or continuously when run in asserts enabled.
The counter is then updated only in RAM, and written at close of the
file. If the close fails, the correct number can be computed from the
file size, and if this is not equal to the stored number it is a strong
evidence that YaCY was not shut down properly.
To preserve consistency, the complete storage-routine had to be re-written.
Another change enhances read of nodes in some cases, where the data-tail
can be read together with the data-head. This saves another IO lookup during
each DB node fetch.
Includes also many small bugfixes.
IF ANYTHING GOES WRONG, ALL YOUR DATA IS LOST: PLEASE MAKE A BACK-UP
git-svn-id: https://svn.berlios.de/svnroot/repos/yacy/trunk@3375 6c8d7289-2bf4-0310-a012-ef5d649a1542
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