hello, i do some more tests to investigate ...
* When the table is read only by a single user (or very few user) speed is fast (around 30 ms by select) * when the table is read by more users (around 50), then the speed go down ! around 500 ms by select * When the table is also updated by some writer, then the speed completely fall down, 1200 ms by select :( But on other table, with even more records, same amount of select / insert / update / seconds, but without any varchar(10000) field then speed stay always around 13 ms So remembered the table is simply : CREATE TABLE DESCRIPTIONS ( IDObj VARCHAR(15) NOT NULL, type SMALLINT NOT NULL, Lang VARCHAR(3) NOT NULL, Descr VARCHAR(10000), PRIMARY KEY (IDObj, type, Lang) ); Why a varchar(10000) field (if it's because of the varchar(10000) field, still not sure) can slow down so much the select ? remembered than even select ... where id not exist => also 1200 ms ! what i can do to speed it up ? --- In [email protected], "nathanelrick" <nathanelrick@...> wrote: > > hello, > > the table : > > CREATE TABLE DESCRIPTIONS > ( > IDObj VARCHAR(15) NOT NULL, > type SMALLINT NOT NULL, > Lang VARCHAR(3) NOT NULL, > Descr VARCHAR(10000), > PRIMARY KEY (IDObj, type, Lang) > ); > > With around 40 millions records > > now the query : > > select Descr From DESCRIPTIONS where (IDObj='XXX') AND (type = 1) > > => 1200 ms to return only one reccord :( > the speed is the same if xxx not exist ! > > the plan used: > PLAN (DESCRIPTIONS INDEX (RDB$PRIMARY135)) > > what is wrong ? > > on some other table with around the same number of rec but no VARCHAR(10000) > field then the return is in around 40 ms ! >
