Oracle 1Z0-873 Online Practice Questions and Exam Preparation

Oracle 1Z0-873 Online Questions & Answers

• Question 71:

  Which of the following are requirements for InnoDB binary portability?

  A. Both machines must use the same operating system.
  B. Database and table names must use lowercase format.
  C. Both machines must use two's-complement integer arithmetic.
  D. Both machines must use IEEE floating-point format or contain no floating-point columns.
  B. Database and table names must use lowercase format.
  C. Both machines must use two's-complement integer arithmetic.
  D. Both machines must use IEEE floating-point format or contain no floating-point columns.

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  29.4. The InnoDB Engine

  The tablespace storage format is portable, so InnoDB files can be copied directly to another host and used by a server there. The conditions for InnoDB portability are given at Section 32.3.4.

  32.3.4. Conditions for Binary Portability

  MyISAM tables and InnoDB tablespaces are binary portable from one host to another if two conditions are met:

  Both machines must use two's-complement integer arithmetic. Both machines must use IEEE floating- point format, or else the tables must contain no floating-point columns (FLOAT or DOUBLE). A third condition for InnoDB binary portability

  is that you should use lowercase names for databases and tables.

• Question 72:

  Which of the following would be the effect of setting REFERENCES with ON UPDATE CASCADE?

  A. Changes to the parent record would be disallowed if there were any corresponding child records.
  B. Records could only be updated and not deleted regardless if they have any corresponding child records.
  C. Changes made to the parent record are passed down to the corresponding child records.
  C. Changes made to the parent record are passed down to the corresponding child records.

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  29.4.6. Using Foreign Keys

  It specifies what actions to take if records are modified in the referenced table. The foreign key definition shown specifies the CASCADE action for both UPDATE and DELETE operations. This means that changes in the parent table are

  cascaded down to the child table. If you change a Code value in the CountryParent table, InnoDB changes any corresponding CityChild records with that value in the CountryCode column to match. If you delete a CountryParent record,

  InnoDB also deletes any CityChild records with the same country code.

• Question 73:

  When running the MySQL server under Windows, the --console option is used to display server errors in the console window.

  A. True
  B. False
  A. True

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  24.2.2. Running MySQL Server Manually on Windows

  If the server does not start properly, check the error log in the data directory to see why. Alternatively, to display diagnostic output in the console window instead, invoke the server with the --console option.

• Question 74:

  The MySQL server host crashes at 10:00 in the morning, and is brought back online at 10:30. In order to ensure that all data are consistent, a copy is first made of the table, tablespace and log files currently on the server host, and these files are then restored from a backup made at 03:00 the same morning. What should be done in order to bring the database to the state it was at just before the server host crashed?

  A. The mysql_restore utility should be used to update the server to its last known state.
  B. The binary logs recorded after the backup at 03:00 should be re-applied to make the database file consistent with the state just before the crash.
  C. The procedure described is wrong; instead, the mysqlcheck utility should be used and only if that fails should backup copies be restored.
  D. Once the backup files from 03:00 have been restored, there is nothing more that can be done to restore the database files.
  B. The binary logs recorded after the backup at 03:00 should be re-applied to make the database file consistent with the state just before the crash.

• Question 75:

  Complete the following sentence.

  The INFORMATION_SCHEMA.SCHEMATA table contains information about ...

  A. ... the table structure for all databases.
  B. ... all of the tables, triggers and views for every database.
  C. ... all of the databases on the server, such as name, character set and collation.
  D. ... every database's structure including tables, triggers, stored routines, views, etc.
  C. ... all of the databases on the server, such as name, character set and collation.

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  A schema is a database, so the SCHEMATA table provides information about databases.

  This information consists of:

  CATALOG_NAME

  SCHEMA_NAME (Database)

  DEFAULT_CHARACTER_SET_NAME

  DEFAULT_COLLATION_NAME

  SQL_PATH

  References:

• Question 76:

  Which of the following statements are true for InnoDB?

  A. InnoDB is enabled by default.
  B. Tablespace and log files have to be configured explicitly to be created.
  C. InnoDB is not enabled by default.
  D. Tablespace and log files will be created even if not configured explicitly.
  A. InnoDB is enabled by default.
  D. Tablespace and log files will be created even if not configured explicitly.

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  29.1. MySQL Storage Engines

  For example, the InnoDB storage engine is included in all binary distributions. If you build MySQL from source, InnoDB is included by default unless you specify the --without-innodb configuration option. For a server that has the InnoDB

  storage engine included, support may be disabled at startup with the --skip- innodb option.

  29.4.7. Configuring and Monitoring InnoDB

  A server that has InnoDB enabled uses a default configuration for its tablespace and log files unless you provide configuration options.

  29.4.7.1 Configuring the InnoDB Tablespace

  If you don't specify any tablespace configuration options at all, InnoDB creates a shared tablespace consisting of a single 10MB auto-extending regular file named ibdata1 in the data directory.

• Question 77:

  Assume you compile MySQL from source and invoke configure with the following options.

  --with-charset=latin1 --with-extra-charsets=utf8,ucs2

  Compared to a standard binary installation that contains many more character sets, which of the following statements is/are true?

  A. The compiled version will use less disk space, because only a few character sets will be installed on disk.
  B. The compiled version will use less memory, because only a few character sets will be loaded by the server.
  C. The compiled version will use less file handles, because only a few files need to be opened when the server is started.
  A. The compiled version will use less disk space, because only a few character sets will be installed on disk.
  B. The compiled version will use less memory, because only a few character sets will be loaded by the server.

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  27.1. Performance Issues To reduce the amount of disk space required by character sets for your MySQL installation and the amount of memory used by the server as it runs, don't select unneeded character sets when you configure MySQL. This requires that you compile MySQL from source rather than using a precompiled binary distribution.

• Question 78:

  When specifying options, which of the following are valid advantages of using options files over parameters on a command line?

  A. Options will not need to be specified every time the server starts.
  B. All options can be consolidated to one file and a single point of reference.
  C. Certain options can be specified only in options files but not on the command line
  A. Options will not need to be specified every time the server starts.
  B. All options can be consolidated to one file and a single point of reference.

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  Option files provide a convenient way to specify commonly used options so that they need not be entered on the command line each time you run a program. http://dev.mysql.com/doc/refman/5.1/en/option- files.html Table 5.2. System Variable Summary shows that all cmd-line options are also available for the option file with no exclusions. http://dev.mysql.com/doc/refman/5.0/en/server-system-variables.html

• Question 79:

  The OPTIMIZE TABLE command should be used...

  A. To increase performance by defragmenting the table.
  B. To improve performance by sorting indexes.
  C. To improve performance by updating index statistics.
  D. To correct problems with a MyISAM table that have become corrupted.
  E. To check a tables structure to see if it may have been damaged and needs repair.
  A. To increase performance by defragmenting the table.
  B. To improve performance by sorting indexes.
  C. To improve performance by updating index statistics.

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  30.2.4. OPTIMIZE TABLE

  The OPTIMIZE TABLE statement cleans up a MyISAM table by defragmenting it. This involves reclaiming unused space resulting from deletes and updates, and coalescing records that have become split and stored non-contiguously.

  OPTIMIZE TABLE also sorts the index pages if they are out of order and updates the index statistics.

• Question 80:

  mysqldump can be instructed to include commands to drop and recreate tables before trying to create or load data.

  A. True
  B. False
  A. True

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  32.4.2. Making Text Backups with mysqldump --add-drop-table Instructs mysqldump to precede the dump output for each table with a DROP TABLE statement that drops the table. This option ensures that when you reload the dump output, the reload operation removes any existing copy of the table before re-creating it.