Oracle
1Z0-027 · Question #6
You are evaluating the performance of a SQL statement that accesses a very large table, and have run the following query producing the output shown: For which two reasons would the; "physical read…
The correct answer is C. There is an uncommitted transaction that has modified some of the table blocks, causing some "cell E. There are migrated rows in the table, causing some "cell single block physical reads" to be requested. See the full explanation below for the reasoning.
Question
You are evaluating the performance of a SQL statement that accesses a very large table, and have run the following query producing the output shown:
For which two reasons would the; "physical read total bytes" statistic be greater than the "cell physical IO bytes eligible for predicate offload" statistic?
Exhibit
Options
- AThere is an index on the column used in the where clause, causing "cell multiblock physical reads"
- BThe table is an IOT and has an overflow segment, causing "cell multiblock physical reads" to be
- CThere is an uncommitted transaction that has modified some of the table blocks, causing some "cell
- DThe table is an indexed clustered table, causing "cell single block physical reads" to be requested
- EThere are migrated rows in the table, causing some "cell single block physical reads" to be requested
How the community answered
(31 responses)- A3% (1)
- B6% (2)
- C77% (24)
- D13% (4)
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