excessive paging w/ mass inserts into HSQLDB

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Chris Markle - 31 Dec 2003 04:33 GMT

All - Cannot be too precise since I heard this from secondhand from one of
my developers but thought I'd throw it out here and can provide more details
later if needed... He (the developer) is trying to insert roughly 1 million
rows into an HSQLDB database. He notes that 100k inserts or so go very
quickly and efficiently, but then the system begins to go into heavy paging
status. Has anyone encountered anything like this with HSQLDB and if so
maybe you could share what you learned? Chris

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Stephen C. Ferguson - 31 Dec 2003 22:32 GMT

I think that HSQLDB puts everything into memory. When the physical memory
is used up, it will start paging. You can periodically monitor the JVM
memory allocated and memory used. The following is code that can be used for
monitoring memory:

Runtime r = Runtime.getRuntime();
System.out.println("Allocated JVM Memory: " +
String.valueOf(r.totalMemory()).toString() + ", Free JVM Memory: " +
String.valueOf(r.freeMemory()).toString());

When the allocated memory is almost equal to the physical memory of the
computer, you will begin noticing the paging.

Steve

> All - Cannot be too precise since I heard this from secondhand from one of
> my developers but thought I'd throw it out here and can provide more details
[quoted text clipped - 3 lines]
> status. Has anyone encountered anything like this with HSQLDB and if so
> maybe you could share what you learned? Chris

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Thomas Kellerer - 01 Jan 2004 11:13 GMT

Chris Markle schrieb:

You could try to use cached tables which are not stored in memory. This is
described in the HSQLDB docs

Thomas

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excessive paging w/ mass inserts into HSQLDB

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