Tag: databases
Questions Related to databases
-
RMAN prompt
-
SQLPLUS prompt
-
Oracle Enterprise Manager 11g (OEM)
-
DRA prompt
-
rman > list failure;
-
rman > report failure;
-
rman > diagnose failure;
-
rman > advise failure;
-
rman > repair failure preview;
-
rman > repair failure;
-
database
-
datafile
-
tracefile
-
spfile
-
controlfilecopy
-
flash recovery area
-
ZLIB compression gives better compression ratio in comparison to BZIP2 compression
-
BZIP2 compression gives better compression ratio in comparison to ZLIB compression
-
ZLIB compression consumes much lesser CPU in comparison to BZIP2 compression
-
BZIP2 compression consumes much lesser CPU in comparison to ZLIB compression
-
ZLIB compression comes with additional licensing cost. BZIP2 compression comes with no additional cost
-
BZIP2 compression comes with additional licensing cost. ZLIB compression comes with no additional cost
-
rman > configure compression algorithm ‘zlib’;
-
rman > configure compression algorithm ‘zlib11g’;
-
rman > set compression algorithm ‘zlib’;
-
rman > set compression algorithm ‘zlib11g’;
-
Scenario 1: Backup 2 datafiles each of 20 GB datafile using 4 RMAN channels. Use the default setting for all RMAN channels
-
Scenario 2: Backup 2 datafiles each of 20 GB datafile using 4 RMAN channels. Each channel backs up 2 datafiles at the same time with “parallel=2”
-
Scenario 3: Backup 2 datafiles each of 20 GB size using 4 RMAN channels. Each channel backs up data with “section size=5GB"
-
Scenario 4: Backup 2 datafiles each of 20 GB datafile using 4 RMAN channels. Each channel backs up 2 datafiles at the same time with “parallel backups=2”
-
You can use group functions in any clause of a select statement
-
You can use group functions only in the column list of the SELECT statement by grouping on the single row columns
-
You can pass column names, expressions, constants or functions as parameters to a group function
-
You cannot group the rows of a table by more than one column while using group functions
-
SELECT SUBSTR('Hello',) FROM dual;
-
SELECT INITCAP(TRIM('Hello World',1,1)) FROM dual;
-
SELECT LOWER(SUBSTR('Hello World',1,1)) FROM dual;
-
SELECT LOWER(SUBSTR('Hello World',2,1)) FROM dual;
-
SELECT LOWER(TRIM('H' FROM 'Hello World')) FROM dual;
-
Indexes are only used in special cases
-
Indexes are used to make table storage more efficient
-
Indexes rarely make a difference in SQL performance
-
Indexes exist solely to improve query speed.