sql - join two Oracle tables, date to not overlapping date ranges -

-

i have 2 tables:

  • trips: id_trip, id_object, trip_date, delta (8980026 rows)
  • ranges: id_range, id_object, date_since, date_until (18490 rows)

i need optimize following select statement 

  select r.id_range, sum(t.delta) sum_deltas     trips t,          ranges r    t.id_object = r.id_object      , t.trip_date between r.date_since , r.date_until group r.id_range

according condition there 1 matching row trip in 'ranges'

  • the trips table growing, there no updates or deletions
  • table ranges may change time time in way (deletions, updates, inserts), function based index not way :(
  • there indexes on id_object (in both tables) , date_since (in trips)

does have idea how speed things up, possible?

it's possible speed things up; may not worth time / effort / money / disk-space / additional overheads etc.

firstly please use explicit join syntax. it's been sql standard few decades , helps avoid lot of potential errors. query become:

select r.id_range, sum(t.delta) sum_deltas   trips t   join ranges r     on t.id_object = r.id_object    , t.trip_date between r.date_since , r.date_until  group r.id_range

this query imply need 2 indexes - unique if possible. on ranges should have index on id_object, date_since, date_until. index on trips id_object, trip_date. if trips smaller might consider adding delta on end of index never enter table @ index scan. stands you're going have table access index rowid.

having written problem may different. you're going full-scanning both tables query. problem might indexes. if optimizer using indexes it's possible you're doing index unique/range scan each id_object in trips or ranges , then, because of use of columns not in indexes doing table access index rowid. can massively expensive.

try adding hint force full-scan of both tables:

select /*+ full(t) full(r) */ r.id_range, sum(t.delta) sum_deltas   trips t   join ranges r     on t.id_object = r.id_object    , t.trip_date between r.date_since , r.date_until  group r.id_range

Comments

Post a Comment

Popular posts from this blog

django - How can I change user group without delete record -

-
on website user have 1 group. , user can change group. it's made user.groups.clear() and user.groups.add(new_group) but it's not efficient, because there 2 sql query: delete, insert. how can change group update query? user , group related each other using manytomanyfield . means intersection table exists relating both entities, , if don't specify model map (using through attribute) django creates 1 you. looking @ sources django.contrib.auth.models see that's case. fortunatly, can access intermediary model using through attribute of manager (in case, user.groups.through ). can use regular model. example: >>> alice = user.objects.create_user('alice', 'alice@example.com', 'alicepw') >>> employee = group.objects.create(name='employee') >>> manager = group.objects.create(name='manager') >>> alice.groups.add(employee) >>> alice.groups.all() [<group: employee...
Read more

java - Need to add SOAP security token -

-
i need set custom soap header attribute on jax-ws generated webservice client. case webservice calls must go through proxy server requiring specific token (recieved web request header) present in soap request header. e.g.: 1 carserviceservice service = null; 2 service = new carserviceservice(new url(url), new qname(qname); 3 carserviceendpoint port = service.getcarserviceport(); it seems in line 3 wsdl retrieved , call fails due missing security token. 1 point direction on how done? a detailed example has been mentioned here: creating , deploying jax-ws web service on tomcat 6 this article shows how create , use security token .
Read more

java - EclipseLink JPA Object is not a known entity type -

-
i have strange problem eclipselink , object want persist. have 1 object (keypointlistimpl) stores object keypointimpl in list. persisting keypointimpl objects works great if try persist keypointlistimpl object java.lang.illegalargumentexception says object keypointimpl isn't known entity type. here keypointimpl code: @entity @table(name="keypoints") public class keypointimpl implements keypoint { @id @generatedvalue(strategy = generationtype.identity) private int id; @enumerated(enumtype.string) private detectortype keypointtype; private float x; private float y; private float size; private float angle; private float response; private int octave; private int classid; ... } here keypointlistimpl code: @entity @table(name="keypointlists") public class keypointlistimpl implements keypointlist { @id @generatedvalue(strategy = generationtype.identity) private int id; @onetoone(cascade={ca...
Read more