Significance of specific database parameter difference

From: Pap <oracle.developer35_at_gmail.com>
Date: Tue, 20 Apr 2021 16:35:15 +0530
Message-ID: <CAEjw_fiakPCwkJivEv7a_=ziPkNaDY14dR=maNETzg-kFL7wLQ_at_mail.gmail.com>



Hello All, we are moving from HP to Exadata - X8. Along with this we are also moving from current Oracle version 11.2.0.4 to 19C. And below are a few of the differences in parameters we see between old and new databases. New database(which is not yet live) holds mostly default setup only. But the existing database has below non default setup(Around ~12 parameters), And I don't know if those non default setups in the old/existing database is really helping us anyway. So wanted to understand if it's safe to go by all the defaults(as it's mentioned below) for the new database? Or any of these non default parameters from existing databases is really critical to be double checked/verified thoroughly, so that we may need to move those as it is to the new database?

*Existing environment (11.2, HP):- *

_buffered_publisher_flow_control_threshold = 500000

_capture_publisher_flow_control_threshold =500000

_enable_query_rewrite_on_remote_objs = true

_optimizer_cost_based_transformation = linear

nls_sort = 'BINARY'

optimizer_dynamic_sampling=0

optimizer_index_caching=100

optimizer_index_cost_adj=1

optimizer_secure_view_merging=FALSE

query_rewrite_enabled=FALSE

optimizer_mode=FIRST_ROWS

session_cached_cursors=0

*New environment- (19C, Exadata - X8):- *

_buffered_publisher_flow_control_threshold = null

_capture_publisher_flow_control_threshold =null

_enable_query_rewrite_on_remote_objs = NULL

_optimizer_cost_based_transformation = null

nls_sort =NULL

optimizer_dynamic_sampling=2

optimizer_index_caching=0

optimizer_index_cost_adj=100

optimizer_secure_view_merging=TRUE

query_rewrite_enabled=TRUE

optimizer_mode=ALL_ROWS
session_cached_cursors=200

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Received on Tue Apr 20 2021 - 13:05:15 CEST

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