Just to update that I have tried this on versions 1.3.161 and 1.3.169 and 
the there's no change in time taken.

On Sunday, 4 November 2012 19:28:23 UTC+5:30, Manik Dhawan wrote:
>
> I have a table with 18 columns with a primary key and 8 indexes. If I make 
> a usual connection to H2 DB (embedded mode) and update the non-index field 
> of this table, it takes around 20 seconds in H2 console to update 50000 
> records. However, if I set MVCC=true in connection string and then try to 
> update SAME 50000 records, the table does not get updated for even more 
> than 30 minutes. I am call this update statements from H2 console here.
>
> Schema below
>
> CREATE TABLE TEMP ( SWITCHIPADDRESS VARCHAR(16), ID BIGINT NOT NULL 
> IDENTITY, MACADDRESS VARCHAR(14), USERID VARCHAR(32), TIMESTMP TIMESTAMP 
> NOT NULL, LINKCOUNT INTEGER, HASLINKTOSWITCH BOOLEAN, LINKIPADDR 
> VARCHAR(16), IFINDEX INTEGER, PORT INTEGER, SLOT INTEGER, VLANID INTEGER, 
> IFSPEED INTEGER, IFADMINSTATUS INTEGER, PORTDUPLEXMODE INTEGER, UNP 
> VARCHAR(32), DOMAIN INTEGER, DISPOSITION INTEGER, PRIMARY KEY (ID) )
>
> Indexes
>
> KEY ForwardIdx (SwitchIPAddress,MACAddress,slot,port), KEY ForwardSwIPIdx(
> SwitchIPAddress), KEY ForwardMACIdx (MACAddress), KEY ForwardSlotIdx (slot), 
> KEYForwardPortIdx (port), KEY ForwardVlanIdx (VlanID), KEY UserIdIdx (
> UserId), KEYUNPIdx (UNP)
>
> I can see in the trace log file that thousands of keys are first getting 
> removed and then getting added which is probably taking time. But I wonder, 
> why would key realignment required when what is being done is a simple 
> update on non-idx field.The problem remains even if I have just 1 index 
> which is used in where clause.
>
> Can someone please let me know how to speed this up and improve update 
> performance out here. Is deletion and then addition of keys by design
>
> Our application is multi-threaded and we are getting "Timeout error trying 
> to lock table" issues for which I have added MVCC=true in the connection 
> line and now ran into another problem.
>
> Thanks
>

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