Thanks, Noel! But here you are trying to workaround BitField growth while it should not grow infinitely at first. Nevertheless your optimization can be helpful. I've found out that it was really id leak: in CreateTable.update() we allocate object id but since this is a session local object it is not getting stored into meta table, then in DropTable we call Database.removeMeta, can't find meta entry to drop and don't clear id bit. I fixed it and submitted pull request on Github.
Sergi 2015-04-14 17:39 GMT+03:00 Noel Grandin <[email protected]>: > > > On 2015-04-14 03:04 PM, Sergi Vladykin wrote: > >> Guys, >> >> There is an important performance issue with Database.allocateObjectId(). >> Over time it becomes slower and slower. >> >> > Does this patch help? > > Index: src/main/org/h2/engine/Database.java > =================================================================== > --- src/main/org/h2/engine/Database.java (revision 6118) > +++ src/main/org/h2/engine/Database.java (working copy) > @@ -920,6 +920,7 @@ > session.log(meta, UndoLogRecord.DELETE, found); > } > objectIds.clear(id); > + objectIdsLastClearBit = Math.min(objectIdsLastClearBit, > id); > if (SysProperties.CHECK) { > checkMetaFree(session, id); > } > @@ -1421,14 +1422,17 @@ > } > } > > + private int objectIdsLastClearBit = 0; > + > /** > * Allocate a new object id. > * > * @return the id > */ > public synchronized int allocateObjectId() { > - int i = objectIds.nextClearBit(0); > + int i = objectIds.nextClearBit(objectIdsLastClearBit); > objectIds.set(i); > + objectIdsLastClearBit = i; > return i; > > } > > > -- > You received this message because you are subscribed to the Google Groups > "H2 Database" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/h2-database. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "H2 Database" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/h2-database. For more options, visit https://groups.google.com/d/optout.
