SQL JOIN query Optimization with subqueries - sql

Question

I used below subquery for get attached records. i need to know is it Optimized query for my task (seems within three month its exists records more than 10,000 ).then is it support for that data load.?
can i use JOIN keyword instead of this below method.please advice me to sort this out.
currently i'm using postgresql as my backend.
select worker,worktype,paymenttype,sum(output)as totalkgs_ltrs,sum(overkgs)as overkgs_ltrs,sum(workedhrs) as workedhrs,sum(scrap) as scrap,sum(cashworkincome) as cashworkincome,sum(pss) as pss
from (select
comp.name as company,
est.name as estate,
div.name as division,
wkr.name as worker,
txn.date as updateddate,
txn.type as worktype,
txn.payment_type as paymenttype,
txn.names as workedhrs,
txn.norm as norm,
txn.output as output,
txn.over_kgs as overkgs,
txn.scrap as scrap,
txn.cash_work_income as cashworkincome,
txn.pss as pss
from
bpl_daily_transaction_master txn,
res_company comp,
bpl_division_n_registration div,
bpl_estate_n_registration est,
bpl_worker wkr
where
comp.id = txn.bpl_company_id and
div.id = txn.bpl_division_id and
est.id = txn.bpl_estate_id and
wkr.id = txn.worker_id
)as subq
group by worker,worktype,paymenttype
here shows my result when i execute this query
here is the subquery's code & results tagged at bottom section
select
comp.name as company,
est.name as estate,
div.name as division,
wkr.name as worker,
txn.date as updateddate,
txn.type as worktype,
txn.payment_type as paymenttype,
txn.names as workedhrs,
txn.norm as norm,
txn.output as output,
txn.over_kgs as overkgs,
txn.scrap as scrap,
txn.cash_work_income as cashworkincome,
txn.pss as pss
from
bpl_daily_transaction_master txn,
res_company comp,
bpl_division_n_registration div,
bpl_estate_n_registration est,
bpl_worker wkr
where
comp.id = txn.bpl_company_id and
div.id = txn.bpl_division_id and
est.id = txn.bpl_estate_id and
wkr.id = txn.worker_id
this is above main query result and its shows all records

Answer 1

select wkr.name as worker,txn.type as worktype,txn.payment_type as paymenttype,sum(txn.output)as totalkgs_ltrs,sum(txn.over_kgs)as overkgs_ltrs,
sum(txn.names) as workedhrs,sum(txn.scrap) as scrap,sum(txn.cash_work_income) as cashworkincome,sum(txn.pss) as pss
from
bpl_daily_transaction_master txn
inner join res_company comp
on comp.id = txn.bpl_company_id
inner join bpl_division_n_registration div
on div.id = txn.bpl_division_id
inner join bpl_estate_n_registration est
on est.id = txn.bpl_estate_id
inner join bpl_worker wkr
on wkr.id = txn.worker_id
group by wkr.name,txn.type,txn.payment_type
What you are are doing in your subquery is old ANSI SQL -89 syntax for joining tables which is not recommended.
But as far as performance is concerned I don't think there is difference as confirmed on this stackoverflow thread.
According to "SQL Performance Tuning" by Peter Gulutzan and Trudy
Pelzer, of the six or eight RDBMS brands they tested, there was no
difference in optimization or performance of SQL-89 versus SQL-92
style joins. One can assume that most RDBMS engines transform the
syntax into an internal representation before optimizing or executing
the query, so the human-readable syntax makes no difference.