I'm using a firebird embedded 2.5.0.26074 database via latest ado provider which contains a simple table

CREATE TABLE INVENTORY (
ID ID NOT NULL /* ID = VARCHAR(36) NOT NULL */,
EXPIRYTIME EXPIRYTIME NOT NULL /* EXPIRYTIME = BIGINT NOT NULL */,
ITEMSIZE ITEMSIZE /* ITEMSIZE = BIGINT NOT NULL */,
ACCESSCOUNT ACCESSCOUNT DEFAULT 1 NOT NULL /* ACCESSCOUNT = INTEGER DEFAULT 1 NOT NULL */,
LASTACCESSTIME LASTACCESSTIME /* LASTACCESSTIME = TIMESTAMP NOT NULL */
);

To tally the sum of all ITEMSIZE rows two triggers where created on the INVENTORY table to add or subtract the value in ITEMSIZE to a TOTALSIZE Column (Single row) in table STATS as a row was added or removed.

CREATE TABLE STATS (
INSTANCE SMALLINT,
SIZE BIGINT DEFAULT 0);

This did not work as deadlock exceptions kept occurring in the triggers. Someone suggested using a view instead to get the sum of all ITEMSIZE records.

CREATE OR ALTER VIEW SIZEVIEW(ITEMSIZE) AS SELECT CAST(COALESCE(SUM(inventory.itemsize), 0) AS BIGINT) FROM INVENTORY;

This did not work either. The deadlock errors still occur when using this view as follows "SELECT * FROM INVENTORY". Lastly I tried different isolation levels IsolationLevel.ReadCommitted, ReadUncommitted, IsolationLevel.Snapshot but still not joy.

this is the calling code

public T ExecuteScalarQueryAs<T>(string Query)
{
try
{
FbTransaction Transaction = DBConnection.BeginTransaction(IsolationLevel.Snapshot);
using (var FBC = new FbCommand(Query, DBConnection, Transaction))
{
object Value = FBC.ExecuteScalar();
Transaction.Commit();
if (Value != null)
{
return (T)Value;
}

return default(T);
}
}
catch (Exception e)
{
Log.FatalException("Database Execute Scalar Query Exception", e);
throw;
}
}

Have also tried IsolationLevel.ReadCommitted, ReadUncommitted

How can I read the sum of itemsize while items are being removed & and added concurrently? It is not critical that this value is 100% correct but I do need to be able to read it reliably.

Thank you..