The query optimizer is the component of a database management system that attempts to determine the most efficient way to execute a query.
-3
votes
1answer
79 views
want to optimize this query by removing two SELECT and two JOINS
SELECT
t3.transaction_pci_details_id,
t3.terminal_id,
t3.transaction_no,
t4.transaction_id,
t3.transaction_type,
t3.reversal_flag,
t3.transmission_date_time,
t4.retrivel_ref_no,
t3.card_no,
...
3
votes
0answers
47 views
How to count selectivity rows in PostgreSQL 8.2
I have problem with two queries on PostgreSQL v8.2. It seem like the optimizer chooses a wrong index:
db=# explain
select count(*), messagetype, alias
from event
where
templateinfoid = 10 and ...
