Oracle 12c upgrade - user_* dictionary queries are slower

Hi,

We recently upgraded our 10.2.0.5 database to 12.1.0.1 version.While doing unit testing, lot of queries against USER_* dictionary tables are running very slow,(sample one listed below).

I changed cursor_sharing from EXACT to FORCE for oracle 12c version.

Can someone please respond if they experienced same issue.

OS platform: Linux

Very much appreciate your response,

Ravi

SELECT OWNER, CONSTRAINT_NAME, CONSTRAINT_TYPE,
TABLE_NAME, R_OWNER,

R_CONSTRAINT_NAME, STATUS

FROM

USER_CONSTRAINTS WHERE OWNER='Z_QAYCTEST' AND TABLE_NAME='RULE_STRUCTURE_CR'

AND CONSTRAINT_TYPE='P' AND STATUS='ENABLED'

Oracle 10g: Plan:



call count cpu elapsed disk query current rows