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Doing a comparison between various database management systems is a very
delicate task. There are so many factors to take in consideration,
beginning with the hardware configuration till ending with choosing
the queries type. For this reason we do not publish comparisons
but we give only some indications and we put to disposition of sources
for who wishes to make comparisons his own. If someone wish to compare
picoSQL with other databases, we'll be happy to publish the results.
In order to make of the concurrency tests, we have used the Java
The JavaConcBench.java program creates a
table with three attributes, two numerical ones and textual the third.
Two unique indices are created on the first numerical attribute and on
the textual attribute. The program inserts the first row with the values
"(0, 0, ' First record ')". To this point the program generates some
thread, whose number is specified on the command line. Each thread writes
a row identified by the name that Java assigns to every thread.
Each thread begins therefore a cycle in which it read the first row of
the DB with "select... for update" to lock the row (the
"SuspensiveLock" option must be set to YES). The value of the first
attribute is increased by 1 and the row is rewritten.Then it is rewritten
the characteristic row of the thread putting in the first attribute the
just read number and in the second attribute the count of number of
operation. All the thread approach therefore a same row, so simulating
one condition of elevated concurrency. The correctness of the concurrency
is guaranteed by the fact that the first attribute in the table,
which is bind to a unique index, does not join duplicated in any moment.
The program finishes after 10'000 operations executed from all the thread.
Increasing the number of thread therefore the number of operations does not
change and therefore the optimal result is had when the program employs
the same time launched with a number whichever of thread.
Last update: 2002-10-02