Change in ovirt-engine[master]: db: drop redundant indexes from db

[Code Review]

>From Martin Peřina <mperina at redhat.com>:

Martin Peřina has submitted this change and it was merged. ( https://gerrit.ovirt.org/80919 )

Change subject: db: drop redundant indexes from db
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db: drop redundant indexes from db

In Postgres a primary key implies a unique index implicitly.
Therefor, there is no need to create an index explicitly that is
identical to columns on which the PK is defined.

This patch removes redundant indexes from the database.

The duplicate indexes were found using the following query:

SELECT pg_size_pretty(SUM(pg_relation_size(idx))::BIGINT) AS SIZE,
       (array_agg(idx))[1] AS idx1, (array_agg(idx))[2] AS idx2,
       (array_agg(idx))[3] AS idx3, (array_agg(idx))[4] AS idx4
FROM (
    SELECT indexrelid::regclass AS idx, (
        indrelid::text ||E'\n'|| indclass::text ||E'\n'|| indkey::text ||E'\n'||
        COALESCE(indexprs::text,'')||E'\n' || COALESCE(indpred::text,'')) AS KEY
    FROM pg_index) sub
GROUP BY KEY HAVING COUNT(*)>1
ORDER BY SUM(pg_relation_size(idx)) DESC;

The results were:

engine_1483889=# \d idx_vm_ovf_generations_vm_guid
Index "public.idx_vm_ovf_generations_vm_guid"
 Column  | Type | Definition
---------+------+------------
 vm_guid | uuid | vm_guid
btree, for table "public.vm_ovf_generations"

engine_1483889=# \d vm_ovf_generations_pkey
Index "public.vm_ovf_generations_pkey"
 Column  | Type | Definition
---------+------+------------
 vm_guid | uuid | vm_guid
primary key, btree, for table "public.vm_ovf_generations"

engine_1483889=# \d idx_engine_backup_log
      Index "public.idx_engine_backup_log"
 Column  |           Type           | Definition
---------+--------------------------+------------
 scope   | character varying(64)    | scope
 done_at | timestamp with time zone | done_at
unique, btree, for table "public.engine_backup_log"

engine_1483889=# \d engine_backup_log_pkey
      Index "public.engine_backup_log_pkey"
 Column  |           Type           | Definition
---------+--------------------------+------------
 scope   | character varying(64)    | scope
 done_at | timestamp with time zone | done_at
primary key, btree, for table "public.engine_backup_log"

engine_1483889=# \d idx_event_notification_hist
Index "public.idx_event_notification_hist"
    Column    |  Type  |  Definition
--------------+--------+--------------
 audit_log_id | bigint | audit_log_id
btree, for table "public.event_notification_hist"

engine_1483889=# \d idx_event_notification_hist_audit_log_id
Index "public.idx_event_notification_hist_audit_log_id"
    Column    |  Type  |  Definition
--------------+--------+--------------
 audit_log_id | bigint | audit_log_id
btree, for table "public.event_notification_hist"

engine_1483889=# \d idx_supported_cluster_features
Index "public.idx_supported_cluster_features"
   Column   | Type | Definition
------------+------+------------
 cluster_id | uuid | cluster_id
 feature_id | uuid | feature_id
unique, btree, for table "public.supported_cluster_features"

engine_1483889=# \d pk_supported_cluster_features
Index "public.pk_supported_cluster_features"
   Column   | Type | Definition
------------+------+------------
 cluster_id | uuid | cluster_id
 feature_id | uuid | feature_id
primary key, btree, for table "public.supported_cluster_features"

Change-Id: I7760ccf64af99b243a87e1344eb0d2b6caadaeb3
Signed-off-by: emesika <emesika at redhat.com>
---
M packaging/dbscripts/common_sp.sql
A packaging/dbscripts/upgrade/04_02_0510_drop_redundant_indexes.sql
2 files changed, 20 insertions(+), 0 deletions(-)

Approvals:
  Martin Peřina: Looks good to me, approved
  Eli Mesika: Verified
  Jenkins CI: Passed CI tests



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Gerrit-MessageType: merged
Gerrit-Change-Id: I7760ccf64af99b243a87e1344eb0d2b6caadaeb3
Gerrit-PatchSet: 3
Gerrit-Project: ovirt-engine
Gerrit-Branch: master
Gerrit-Owner: Eli Mesika <emesika at redhat.com>
Gerrit-Reviewer: Arik Hadas <ahadas at redhat.com>
Gerrit-Reviewer: Eli Mesika <emesika at redhat.com>
Gerrit-Reviewer: Jenkins CI
Gerrit-Reviewer: Martin Peřina <mperina at redhat.com>
Gerrit-Reviewer: Moti Asayag <masayag at redhat.com>
Gerrit-Reviewer: gerrit-hooks <automation at ovirt.org>