First Query

[former_SQLA_member1694872]

After starting the database when the first query takes longer to run. For example, a simple query to get the date of the last sale, after this consultation the other run faster:

select max(date_sale) as data_sale from tbsales, tbsales_tribute
where tbsales.emp = tbsales_tribute.emp
and tbsales.sale = tbsales_tribute.sale
and tbsales.emp = 1
and tbsales_tribute.type = 5

or

select max(date_sale) as data_sale
from tbsales
key join tbsales_tribute
where tbsales.emp = 1 
and tbsales_tribute.type = 5

or

select max (date_sale) as data_sale
from tbsales
join tbsales_tribute on
(tbsales_tribute.emp = tbsales.emp and tbsales_tribute.sale = tbsales.sale)
where tbsales.emp = 1
and tbsales_tribute.type = 5

Which of these queries is more optimized?

(a friend told me that we should always use the sybase key join instead of join, key join the reserved word always makes the query more optimized, so pe truth? where I can find material about?)

[VolkerBarth]

FWIW: "JOIN" and "KEY JOIN" are sematically identical if you don't specify a join condition (i.e. a " ON ...") afterwards. From the docs:

Key join is the default in SQL Anywhere when all the following apply:
* the keyword JOIN is used.
* the keywords CROSS, NATURAL or KEY are not specified.
* there is no ON clause.

You may tell that your friend.

[former_SQLA_member1694872]

Ok .. I'm reading the documentation and I will pass on to my friend this link.

[former_SQLA_member1694872]

Hi,

Working with an ERP that features integration with Inventory, Sales, bank, cash, documents payable, receivable documents, accounting, tax paying employees. And every now and then is always showing signs of sluggishness in queries. Some here have suggested deleting some data (say the database is too "bloated"), but I do not think so because the databases have averaged about 3GBytes the 5GBytes, good servers, and I'm always trying to improve their performance through REORGANIZE TABLES, delete and create statistics, initializing the memory bank with larger cache and are already used the contig.exe to defragment the database file already ran the index consultant, but, the last time (about 1 month or less) back to slow again, the databases of customers are increasing, and now who never complained of are calling for technical support and "burning down". I do not know what else to do. Are already thinking about changing to DBMS.

[VolkerBarth]

@Walmir: As you post these general experiences, I guess you current performance-related questions are still unanswered. (Sorry, I don't have the skills to answer them.)

In case my observation is correct, I'd recommend to re-activate these questions, say by adding a comment...

[former_SQLA_member1694872]

To implement the Index Consultant. Leave for 10 minutes and running already been captured 8500 queries. How long you must leave this option running?