Querying multiple intersection tables against another table for row exists

Question

Hi all,
Running on:
Oracle9i Enterprise Edition Release 9.2.0.8.0 - 64bit Production
With the Partitioning and OLAP options
JServer Release 9.2.0.8.0 - Production
I am setting up email subscription service for news service website. News articles are tagged with multiple audiences, topics, regions and departments. Legacy data model we're dealing with implements one intersection table (M:N) for each of audience, topic, region and department lookup table and main news article table.
Email subscribers can pick any combination of the above options (audience, dept etc..) to customize the content of their email. Emails will be either daily or weekly digests of articles of interest, based on their chosen options.
The subscriber options are captured in one table, each option type being its own column. I'm trying to write one query to basically extract all articles that match a given subscriber's chosen options.
create table audiences(articleid number, audienceid number);
create table topics(articleid number, topicid number);
create table regions(articleid number, regionid number);
create table depts(articleid number, deptid number);
create table subscriber_options(emailid number,audienceid number,topicid number, regionid number, deptid number);
insert into audiences(articleid,audienceid)
SELECT
ceil(dbms_random.value(1,10)),
ceil(dbms_random.value(1,50))
from all_objects where rownum < 100;
insert into topics(articleid,topicid)
select
ceil(dbms_random.value(1,10)),
ceil(dbms_random.value(1,50))
from all_objects where rownum < 100;
insert into regions(articleid,regionid)
select
ceil(dbms_random.value(1,10)),
ceil(dbms_random.value(1,50))
from all_objects where rownum < 100;
insert into depts(articleid,deptid)
select
ceil(dbms_random.value(1,10)),
ceil(dbms_random.value(1,50))
from all_objects where rownum < 100;
INSERT INTO subscriber_options (
   EMAILID, audienceid, topicid,
   regionid, deptid)
select
ceil(dbms_random.value(1,10)),
ceil(dbms_random.value(1,50)),
ceil(dbms_random.value(1,50)),
ceil(dbms_random.value(1,50)),
ceil(dbms_random.value(1,50))
from all_objects where rownum < 100;
commit;If a subscriber hasn't chosen any options, then no rows will exist in the subscriber_options table, which implies that they will receive all articles.
I am struggling with this query.. can this be achieved using only 1 query or is this a case where some PL/SQL is required?
All I really want to know is if a given subscriber option matches an option for a given article, using the following boolean logic (topic OR audience) AND dept AND region.
Because I'm more concerned with row existence, I thought of using the "EXISTS" with subquery approach.
Thanks for tips and advice.

Answer 1

Well.. a little persistence, and I think I cracked this nut. ;-)
WITH instant_subscribers AS
     (SELECT   email_subscriber_id, email_subscriber.subscriber_email,
               email_subscriber.subscriber_first_name,
               email_subscriber.subscriber_last_name,
               email_subscriber.subscriber_identifier_code,
               email_subscriber.languageid, COUNT (newscreatorid)
                                                                 dept_options,
               COUNT (newscategoryid) topic_options,
               COUNT (newscoveragespatialid) region_options,
               COUNT (newsaudiencetypeid) audience_options
          FROM email_subscriber LEFT OUTER JOIN subscriber_option
               USING (email_subscriber_id)
         WHERE email_subscriber.subscription_frquncy_type_id = 1
           AND email_subscriber.subscription_status_id = 2
           and email_subscriber_id=53169
      GROUP BY email_subscriber_id,
               email_subscriber.subscriber_email,
               email_subscriber.subscriber_first_name,
               email_subscriber.subscriber_last_name,
               email_subscriber.subscriber_identifier_code,
               email_subscriber.languageid)
SELECT subscr.*, d.*
  FROM instant_subscribers subscr,
       (SELECT ccnews.newsid, ccnews.title, ccnews.embargodate, ccnews.description,
               ccnews.languageid
          FROM ccnews
         WHERE ccnews.embargodate >= TRUNC (SYSDATE - 7)
           AND ccnews.embargodate < TRUNC (SYSDATE)
           AND ccnews.newsstatusid = 2
           AND ccnews.isreadingroom = 'FALSE'
           )  d
WHERE subscr.languageid = d.languageid and ( (subscr.audience_options=0 OR subscr.topic_options=0 OR EXISTS (
                    SELECT NULL
                          FROM subscriber_option INNER JOIN ccnews_audience_rel
                               USING (newsaudiencetypeid, languageid)
                         WHERE subscriber_option.email_subscriber_id =
                                       subscr.email_subscriber_id
                           AND ccnews_audience_rel.newsid = d.newsid))
        OR ( EXISTS (
                 SELECT NULL
                          FROM subscriber_option INNER JOIN ccnews_category_rel
                               USING (newscategoryid, languageid)
                         WHERE email_subscriber_id =
                                       subscr.email_subscriber_id
                           AND ccnews_category_rel.newsid = d.newsid))
   AND (subscr.dept_options = 0 OR EXISTS (
                SELECT NULL
                      FROM subscriber_option INNER JOIN ccnews_creator_rel
                           USING (newscreatorid, languageid)
                     WHERE email_subscriber_id =
                                       subscr.email_subscriber_id
                       AND ccnews_creator_rel.newsid = d.newsid))
   AND (subscr.region_options = 0 OR EXISTS (
                    SELECT NULL
                      FROM subscriber_option INNER JOIN ccnews_coverage_spatial_rel
                           USING (newscoveragespatialid, languageid)
                     WHERE email_subscriber_id =
                                       subscr.email_subscriber_id
                       AND ccnews_coverage_spatial_rel.newsid = d.newsid)) order by d.embargodate DESCI basically outer join my subscriber (supertype) with my subscriber_options (subtype)... and count each option type groupe by subscriber, to determine if they have any options for given type (if count is 0, then they chose "all")
From there, I use this count to "short-circuit" the predicates.. if count=0 OR exists subquery with inner join on chosen options matched to article.
Explain plan reveals the following:
Plan
SELECT STATEMENT  CHOOSECost: 70  Bytes: 727  Cardinality: 1                                                    
     36 SORT ORDER BY  Cost: 70  Bytes: 727  Cardinality: 1                                               
          35 FILTER                                          
               10 TABLE ACCESS BY INDEX ROWID NEWSROOM.CCNEWS Cost: 64  Bytes: 371  Cardinality: 1                                     
                    9 NESTED LOOPS  Cost: 68  Bytes: 727  Cardinality: 1                                
                         7 VIEW NEWSROOM_DEV02. Cost: 4  Bytes: 356  Cardinality: 1                           
                              6 SORT GROUP BY  Cost: 4  Bytes: 121  Cardinality: 1                      
                                   5 FILTER                 
                                        4 NESTED LOOPS OUTER  Cost: 2  Bytes: 605  Cardinality: 5            
                                             2 TABLE ACCESS BY INDEX ROWID NEWSROOM_DEV02.EMAIL_SUBSCRIBER Cost: 1  Bytes: 80  Cardinality: 1       
                                                  1 INDEX UNIQUE SCAN UNIQUE NEWSROOM_DEV02.EMLSUBSR_PK Cardinality: 1 
                                             3 INDEX RANGE SCAN UNIQUE NEWSROOM_DEV02.SUBSCRIBER_OPTION_UQ_IDX Cost: 1  Bytes: 205  Cardinality: 5       
                         8 INDEX RANGE SCAN NON-UNIQUE NEWSROOM.CCNEWS_IN Cost: 1  Cardinality: 317                           
               16 TABLE ACCESS BY INDEX ROWID NEWSROOM.CCNEWS_AUDIENCE_REL Cost: 5  Bytes: 12  Cardinality: 1                                     
                    15 NESTED LOOPS  Cost: 5  Bytes: 39  Cardinality: 1                                
                         12 TABLE ACCESS BY INDEX ROWID NEWSROOM_DEV02.SUBSCRIBER_OPTION Cost: 2  Bytes: 297  Cardinality: 11                           
                              11 INDEX RANGE SCAN UNIQUE NEWSROOM_DEV02.SUBSCRIBER_OPTION_UQ_IDX Cost: 2  Cardinality: 4                      
                         14 BITMAP CONVERSION TO ROWIDS                           
                              13 BITMAP INDEX SINGLE VALUE NEWSROOM.CCNEWS_AUDIENCE_REL_IN                     
               22 TABLE ACCESS BY INDEX ROWID NEWSROOM.CCNEWS_CATEGORY_REL Cost: 5  Bytes: 12  Cardinality: 1                                     
                    21 NESTED LOOPS  Cost: 5  Bytes: 78  Cardinality: 2                                
                         18 TABLE ACCESS BY INDEX ROWID NEWSROOM_DEV02.SUBSCRIBER_OPTION Cost: 2  Bytes: 297  Cardinality: 11                           
                              17 INDEX RANGE SCAN UNIQUE NEWSROOM_DEV02.SUBSCRIBER_OPTION_UQ_IDX Cost: 2  Cardinality: 4                      
                         20 BITMAP CONVERSION TO ROWIDS                           
                              19 BITMAP INDEX SINGLE VALUE NEWSROOM.CCNEWS_CATEGORY_REL_IN                     
               28 TABLE ACCESS BY INDEX ROWID NEWSROOM.CCNEWS_CREATOR_REL Cost: 5  Bytes: 14  Cardinality: 1                                     
                    27 NESTED LOOPS  Cost: 5  Bytes: 41  Cardinality: 1                                
                         24 TABLE ACCESS BY INDEX ROWID NEWSROOM_DEV02.SUBSCRIBER_OPTION Cost: 2  Bytes: 297  Cardinality: 11                           
                              23 INDEX RANGE SCAN UNIQUE NEWSROOM_DEV02.SUBSCRIBER_OPTION_UQ_IDX Cost: 2  Cardinality: 4                      
                         26 BITMAP CONVERSION TO ROWIDS                           
                              25 BITMAP INDEX SINGLE VALUE NEWSROOM.CCNEWS_CREATOR_REL_IN                     
               34 TABLE ACCESS BY INDEX ROWID NEWSROOM.CCNEWS_COVERAGE_SPATIAL_REL Cost: 5  Bytes: 12  Cardinality: 1                                     
                    33 NESTED LOOPS  Cost: 5  Bytes: 39  Cardinality: 1                                
                         30 TABLE ACCESS BY INDEX ROWID NEWSROOM_DEV02.SUBSCRIBER_OPTION Cost: 2  Bytes: 297  Cardinality: 11                           
                              29 INDEX RANGE SCAN UNIQUE NEWSROOM_DEV02.SUBSCRIBER_OPTION_UQ_IDX Cost: 2  Cardinality: 4                      
                         32 BITMAP CONVERSION TO ROWIDS                           
                              31 BITMAP INDEX SINGLE VALUE NEWSROOM.CCNEWS_SPATIAL_REL_IN                     To me it looks pretty good... I'd be curious to know how it looks to a trained eye.. ;-)
I do get my results back as expected...
Edited by: pl_sequel on Sep 24, 2010 4:24 PM