Addenda and Errata

Last update of this page: 2014-08-20

Date Page Description
2014-06-11 19 Original sentence: The selectivity is a value between 0 and 1 representing the fraction of rows filtered by an operation.
Corrected sentence: The selectivity is a value between 0 and 1 representing the fraction of rows that an operation returns.
Reported by Charles Hooper.
2014-06-11 24 In Figure 2-3 two “boxes” contain the same text (Store parent cursor in library cache). The one at the top is right, the one at the bottom is wrong. It should be “Store child cursor in library cache”.
Reported by Charles Hooper.
2014-06-30 43 Original sentence: Because of its success, having been ported to other programming languages like C++, .NET, Perl, and PHP.
Corrected sentence: Because of its success, it has been ported to other programming languages like C++, .NET, Perl, and PHP.
Reported by Ted Persky.
2014-06-01 45/46 The session_info.sql script was renamed. As written at page 46, its new name is session_attributes.sql.
2014-08-20 62 Original sentence: The ALTER SESSION privilege required to execute the previous trigger can’t be granted through a role. Instead, it has to be granted directly to the user executing the trigger.
Corrected sentence: The ALTER SESSION privilege required to execute the previous trigger can’t be granted through a role. Instead, it has to be granted directly to the user creating the trigger.
Reported by Charles Hooper.
2014-07-20 73 Original sentence: The number of executions itself is provided by the “Number of plan statistics captured” value.
Corrected sentence: The number of execution plans itself is provided by the “Number of plan statistics captured” value.
Reported by Charles Hooper.
2014-07-06 106 The query executed against v$osstat contains a wrong WHERE clause. Actually, no where clause should be present.
Reported by Winston Zhang
2014-07-06 111 Original sentence: The following query, which was executed for the same session as the previous one, illustrates how produce a detailed resource usage profile for the processing carried out by a session
Corrected sentence: The following query, which was executed for the same session as the previous one, illustrates how to produce a detailed resource usage profile for the processing carried out by a session
Reported by Philipp Salvisberg
2014-06-30 123 Original sentence: Load map showing the top 5 SQL statement for the time period selected in Figure 4-5
Corrected sentence: Load map showing the top 5 SQL statements for the time period selected in Figure 4-5
Reported by Ted Persky.
2014-06-30 126 Original sentence: Whereas the dynamic performance views described in the last section provide only cumulated statistics about cursors, real-time monitoring provides information that describe how, over time, cursors are executed.
Corrected sentence: Whereas the dynamic performance views described in the last section provide only cumulated statistics about cursors, real-time monitoring provides information that describes how, over time, cursors are executed.
Reported by Ted Persky.
2014-07-20 149 Original sentence: Can you find out what happened and, as a result, prevent it from happenning again?
Corrected sentence: Can you find out what happened and, as a result, prevent it from happening again?
Reported by Charles Hooper.
2014-06-28 185 Original sentence: In fact, without this query transformation, all component queries would be executed idependently before applying the set operator.
Corrected sentence: In fact, without this query transformation, all component queries would be executed independently before applying the set operator.
Reported by Na Jangkeun.
2014-06-28 186 Original sentence: Without this query transformation, both component queries would be executed idependently, and both tables would be accessed twice:
Corrected sentence: Without this query transformation, both component queries would be executed independently, and both tables would be accessed twice:
Reported by Na Jangkeun.
2014-06-11 215 Original sentence: This is especially true for multibyte character sets where each character might take up to three bytes.
Corrected sentence: This is especially true for multibyte character sets where each character might take up to four bytes.
Reported by Philipp Salvisberg.
2014-07-06 215 Original sentence: A row in available for each bucket in a view like user_tab_histograms.
Corrected sentence: A row is available for each bucket in a view like user_tab_histograms.
Reported by Philipp Salvisberg.
2014-08-20 221 Original sentence: For this reason, as of version 12.1, top frequency histograms and hybrid histograms replace height-balanced histograms.
Corrected sentence: To avoid using them, as of version 12.1, top frequency histograms and hybrid histograms are available .
Reported by Charles Hooper.
2014-06-11 226/227 It is not possible to create more than 20 extensions. If you try to create more than 20 extensions, the following error is raised:

ORA-20008: Number of extensions in table <table> already reaches the upper limit (20)
2014-08-20 239 Original sentence: Also note that some features (top frequency histograms, hybrid histograms, and incremental
statistics) only work when dbms_stats.auto_sample_size is specified.
Corrected sentence: Also note that some features (top frequency histograms, hybrid histograms, and incremental
statistics) require that dbms_stats.auto_sample_size is specified.
Reported by Charles Hooper.
2014-08-20 282 Original sentence: This level is available as of version 12.1 only.
Corrected sentence: This level is available as of version 11.2.0.4 only.
Reported by Charles Hooper.
2014-08-20 313 Original sentence: The number of logical reads performed during the execution.
Corrected sentence: The number of blocks accessed through logical reads during the execution.
Reported by Charles Hooper.
2014-08-20 313 Original sentence: The number of physical reads performed during the execution.
Corrected sentence: The number of blocks accessed through physical reads during the execution.
Reported by Charles Hooper.
2014-08-20 313 Original sentence: The number of physical writes performed during the execution.
Corrected sentence: The number of blocks accessed through physical writes during the execution.
Reported by Charles Hooper.
2014-08-20 365 Original sentence: Syntactical errors in hints don’t raise errors.
Corrected sentence: In general, syntactical errors in hints don’t raise errors.
Reported by Charles Hooper.
2014-08-20 371 Original sentence: While processing a SQL statement, the parser checks the syntax of the hints. In spite of this, no error is raised when a hint is found with invalid syntax.
Corrected sentence: While processing a SQL statement, the parser checks the syntax of the hints. In spite of this, except for the oddly behaving change_dupkey_error_index, ignore_row_on_dupkey_index and retry_on_row_change hints, no error is raised when a hint is found with invalid syntax.
Reported by Charles Hooper.
2014-08-20 428 Original sentence: The aim of using a prepared statement is to share a single cursor for all SQL statements and, consequently, to avoid unnecessary hard parses by turning them into soft parses.
Corrected sentence: The aim of using a prepared statement is to share a single cursor for all similar SQL statements (those that would have differed only by literals if bind variables weren’t used) and, consequently, to avoid unnecessary hard parses by turning them into soft parses.
Reported by Charles Hooper.
2014-07-06 478 Original sentence: Inequality (!= or <>), NOT IN, IS NOT NULL conditions, and restrictions based on expressions and functions don’t lead to partition pruning.
Corrected sentence: Inequality (for example, != or <>), NOT IN, IS NOT NULL conditions, and restrictions based on expressions and functions don’t lead to partition pruning.
Reported by Philipp Salvisberg.
2014-07-06 490 Original sentence: That’s because the time needed to build the list of rowids is much smaller, both for B-tree and for bitmap indexes, than the time needed to access the table with them in such situations
Corrected sentence: That’s because the number of logical reads needed to build the list of rowids is much smaller, both for B-tree and for bitmap indexes, than the number of logical reads needed to access the table with them in such situations
Reported by Philipp Salvisberg.
2014-07-06 540 Original sentence: As discussed in the the previous section, if the selectivity of the inner loop is strong, using an index scan for the inner loop makes sense.
Corrected sentence: As discussed in the previous section, if the selectivity of the inner loop is strong, using an index scan for the inner loop makes sense.
Reported by Na Jangkeun.
2014-06-28 548 Original sentence: As a result, idependently of the access paths used to get data, no SORT JOIN operations are required.
Corrected sentence: As a result, independently of the access paths used to get data, no SORT JOIN operations are required.
2014-07-06 559 Original sentence: Although the operation_id column is used to relate the work areas to an operation in the execution plan, the actual_mem_used column shows the size (in bytes), and the tempseg_size columns and tablespace give information about the utilization of temporary space:
Corrected sentence: Although the operation_id column is used to relate the work areas to an operation in the execution plan, the actual_mem_used column shows the size (in bytes), and the tempseg_size and tablespace columns give information about the utilization of temporary space:
Reported by Na Jangkeun.
2014-07-06 569 Original sentence: Therefore, I strongly recommend that you use use join conditions and, consequently, foreign keys and bitmap indexes based on a single column.
Corrected sentence: Therefore, I strongly recommend that you use join conditions and, consequently, foreign keys and bitmap indexes based on a single column.
Reported by Philipp Salvisberg.
2014-07-20 589 Original sentence: This method, called out-of-place refresh, makes sure that the impact on concurrent queries accessing the materialized is minimized.
Corrected sentence: This method, called out-of-place refresh, makes sure that the impact on concurrent queries accessing the materialized view is minimized.
Reported by Na Jangkeun.
2014-06-01 611 From 12.1 onward, the default value of the parallel_min_servers initialization parameter is “cpu_count * parallel_threads_per_cpu * 2″, and not 0 as written.
2014-08-20 671 Original sentence: The following example, based on the reserve_index.sql script, shows that the query optimizer no longer uses the index after rebuilding it with the REVERSE option
Corrected sentence: The following example, based on the reverse_index.sql script, shows that the query optimizer no longer uses the index after rebuilding it with the REVERSE option
Reported by Charles Hooper.

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