Make OpenResearch SQLStore triples available via triplestore.sql workaround

[WolfgangFahl]

Since we have no other proper multi-entity/join triplestore query means use the 2015 Proposal_for_a_View_that_makes_SMW_Triples_available_for_inspection/debugging workaround.

[WolfgangFahl]

see https://github.com/SmartDataAnalytics/OpenResearch/blob/master/migration/scripts/triplestore.sql

[WolfgangFahl]

cat triplestore.sql | mysql or35

[WolfgangFahl]

select count(*) from smw_triples;

[WolfgangFahl]

[Code: 1615, SQL State: HY000]  Prepared statement needs to be re-prepared
mysql --version
mysql  Ver 15.1 Distrib 10.3.25-MariaDB, for debian-linux-gnu (x86_64) using readline 5.2

• https://stackoverflow.com/questions/4380813/how-to-get-rid-of-mysql-error-prepared-statement-needs-to-be-re-prepared
• https://jira.mariadb.org/browse/MDEV-17124
• https://dba.stackexchange.com/questions/183566/what-should-i-set-my-table-definition-cache-to

show variables where variable_name like 'table%'
Variable_name                        Value
table_definition_cache              400
table_open_cache                   2000
table_open_cache_instances        4

see https://mariadb.com/kb/en/server-system-variables/#table_definition_cache

[WolfgangFahl]

root@confident:/etc/mysql/mariadb.conf.d# git diff 50-server.cnf 
diff --git a/mysql/mariadb.conf.d/50-server.cnf b/mysql/mariadb.conf.d/50-server.cnf
index e7e88ef..5673b97 100644
--- a/mysql/mariadb.conf.d/50-server.cnf
+++ b/mysql/mariadb.conf.d/50-server.cnf
@@ -40,6 +40,7 @@ bind-address            = 127.0.0.1
 #max_connections        = 100
 #table_cache            = 64
 #thread_concurrency     = 10
+table_definition_cache  = 3000

 #
 # * Query Cache Configuration

sudo service mysqld restart

[WolfgangFahl]

select count(*) as triplecount
from smw_triples;

triplecount
187941

[WolfgangFahl]

describe smw_triples

Field	Type	Null
subject	varchar(255)	YES
predicate	varchar(255)	YES
object	longtext	YES
TYPE	varchar(9)	NO

[WolfgangFahl]

select 
  predicate,
  count(*) as predicateUsage 
from smw_triples
group by predicate
having predicateUsage>100
order by predicateUsage desc

[WolfgangFahl]

predicate	predicateUsage
IsA	11595
_ERRT	11229
_ERRP	10777
Title	9551
_ERRC	9547
Has_year	9315
Event_type	9159
Has_location_city	8757
Acronym	8655
Homepage	8647
Start_date	8567
Has_location_country	8542
End_date	8487
Has_PC_member	7321
Submission_deadline	5971
Name	5236
Event_in_series	4940
Has_program_chair	3972
Has_Keynote_speaker	3156
Has_general_chair	2950
Notification	2457
Submitted_papers	2336
Accepted_papers	2319
Acceptance_rate	2319
Has_location_state	2243
Camera_ready_due	1311
Has_coordinator	1239
Has_workshop_chair	1099
Has_Average_Acceptance_Rate	1048
Has_Average_5y_Acceptance_Rate	1045
EventSeries_acronym	1040
Abstract_deadline	773
Paper_deadline	705
Field	670
Has_Submitting_link	657
Has_CORE_Rank	586
Has_OC_member	569
Has_tutorial_chair	505
Ordinal	503
Registration_link	411
Has_twitter	404
Subevent_of	374
Has_demo_chair	352
Attendance_fee_currency	277
On_site_regular	255
Early_bird_regular	216
Logo	205
On_site_student	197
Early_bird_student	188
Workshop_deadline	147
Accepted_short_papers	144
Has_local_chair	140
Has_authors	121