Do I have to create another table to put this data??? But, Isn't it redundancy? :-/
The question is: For example:
I have a "clients" table and I have a "taxes" table that is a chield of client.
Is more efficient put fields into client table that contains:
-) the count for paid taxes
-) the count for unpaid taxes
-) the count for all taxes
-) the last tax expiration date
Or is more efficient construct a function that will count this field runtime,
as a view for example, or a simple function.
-) SELECT count(*) from taxes where client=$1 and not nullvalue(dt_pay);
-) SELECT count(*) from taxes where client=$1 and nullvalue(dt_pay);
-) SELECT count(*) from taxes where client=$1;
-) SELECT dt_expiration from taxes where client=$1 order by dt_expiration desc
limit 1;
While having few records in "taxes" table, the function (runtime) work right and
in good time, but when the "taxes" table grows I think the function will run so
slow...
What is correct???
Construct a Function to count runtime? or Create a Trigger to update the
"clients" fields before all action and use those fields in select???
Thanks
Quoting Joel Fradkin <[EMAIL PROTECTED]>:
You could also make a table with just that data in it so you don't have the field in all the records and you don't have to check all the records to see what is next.
I am assuming this is some kind of a flag values used in a batch, if you just need the last id I use max(id)+1.
Joel Fradkin
Wazagua, Inc. 2520 Trailmate Dr Sarasota, Florida 34243 Tel. 941-753-7111 ext 305
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-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Monday, May 02, 2005 3:17 PM To: pgsql-sql@postgresql.org Subject: [SQL] Function or Field?
Hi. What is the better way to store the last record for a translation??? I.E: The data for the last product vendding. What is better: a) Create a field in "product" table and create a Trigger (before insert or update into vendding table) to alter this field. b) Create a view or function that check the all venddings (in vendding table) for the specified product and return the last vendding information?
a) CREATE TABLE products( id serial primary key, description varchar(50), last_vendding date() --Is correct to use this field??? ); CREATE TABLE vendding( id serial primary key, date_ date, product integer references (products) ); CREATE TRIGGER TG_change_products_last_vendding_field on table vendding BEFORE INSERT OR UPDATE FOR EACH ROW EXECUTE procedure change_products_last_vendding();
b) CREATE TABLE products ( id serial primary key, description varchar(50) ); CREATE TABLE vendding( id serial primary key, date_ date, product integer references (products) ); CREATE VIEW last_product_change as SELECT * from vendding order by date_ desc limit 1; --Okay, this view will return the last record and not the last record for a product... but its a example.
I am asking it becouse I have used CLIPPER(dbase) for my old programs and in DBASE the view/check function that will check for each select is not functional. And I need to create a field in all table references, but in DBASE this fields allways broken and I need to recheck it.
Thank you.
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