Left Outer Join bad performance

I`am having very bad performance using outer joins sentences in my quieries.
I read in the internet that FB 1.5 have problems with "outer joins". Is that True ?

if I run this:

Select mp.*, phc.*
From Maestro_Pacientes mp
Left Outer join Paciente_hc phc On mp.Codigo = phc.Paciente
Where mp.Codigo >= 1

the execution plan is this:
Plan
PLAN JOIN (MP INDEX (RDB$PRIMARY58),PHC INDEX (PK_PACIENTE_HC))
Adapted Plan
PLAN JOIN (MP INDEX (INTEG_526),PHC INDEX (PK_PACIENTE_HC))

------ Performance info ------
Prepare time = 0ms
Execute time = 32ms
Avg fetch time = 2.67 ms
Current memory = 1,879,652
Max memory = 2,110,108
Memory buffers = 2,048
Reads from disk to cache = 586
Writes from cache to disk = 0
Fetches from cache = 712

It runs ver fast....
But I need the recordset order By "Codigo"
like thist:

Select mp.*, phc.*
From Maestro_Pacientes mp
Left Outer join Paciente_hc phc On mp.Codigo = phc.Paciente
Where mp.Codigo >= 1 order By mp.Codigo

and the execution plan is this:
Plan
PLAN SORT (JOIN (MP INDEX (RDB$PRIMARY58),PHC INDEX (PK_PACIENTE_HC)))

Adapted Plan
PLAN SORT (JOIN (MP INDEX (INTEG_526),PHC INDEX (PK_PACIENTE_HC)))

------ Performance info ------
Prepare time = 0ms
Execute time = 8s 266ms
Avg fetch time = 688.83 ms
Current memory = 1,883,264
Max memory = 2,110,108
Memory buffers = 2,048
Reads from disk to cache = 15,661
Writes from cache to disk = 0
Fetches from cache = 1,956,941

It takes 8 seconds. too much compare to the other plan.
I see that Firebird make a sort of all the tables involved in the plan.
In table (Maestros_Pacientes) I have 335.000 records. And in table (Paciente_Hc) I have 140.000 records.
The performance Analisis in the second plan says that the indexed reads in
each table are equal to the number of record in each one.
Wath can i do to improve that ?

Sorry for my english ! I speak in spanish.

Try creating an ascending index on the mp.Codigo column and see if there is any improvement !!

I have an index on this field.
And i try other outer joins queries and in all i have bad performance.

Taking a fast look at this I can see a big difference between the 1st and the 2nd test.
I don't think that there is anything else you can do to improve the response time.
What is your Firebird server configuration ? Processor, memory etc ?

I have read that Left outer join creates a Cartesian product , so the server need some time to sort all records.
But in MSSQL the same Database and the same query works fine.
I Carlos Valderrama firebird Web I have read that the is a problem of the FB version and they are working on that.
Until the resolve this problem I will not use leoft Outer joins queries.

Same problem here left outer joins fail dunno why..Does firebird not support left outer joins?
SQLserver does so well

molochgoa,
please don't dig threads, if you have a problem with a query post it with detailed explaination (actual query, table structure, error message, explain plan, whatever ...)
Left outer joins work and well, no carthesian products unless introduced by the one who writes the query

Here is the follow up thread with molochgoa's question