Oracle Magazine Ask Tom Columns

Tom Kyte Headshot Tom Kyte is a database evangelist in Oracle’s Server Technologies division and has worked for Oracle since 1993. He is the author of Expert Oracle Database Architecture (Apress, 2005, 2010) and Effective Oracle by Design (Oracle Press, 2003), among other books.

Pub Date



January/February 2015 On Oracle Database In-Memory Our technologist talks with Oracle product management about Oracle Database 12c’s Oracle Database In-Memory option.
November/December 2014 On Query Tuning Our technologist tunes queries by helping the optimizer optimize.
September/October 2014 On Implicit Conversions and More Our technologist looks at implicit conversions, logic bombs, SQL injection, and reduced access paths—in one question and answer.
July/August 2014 On Table Updates and SQL Plan Baselines Our technologist updates tables quickly via CTAS and optimizes queries for evolution.
May/June 2014 On Oracle Database 12c, Part 5 Our technologist explores the invisible, improves introspection, and expands SQL.
March/April 2014 On Oracle Database 12c, Part 4 Our technologist talks with Oracle product management about Oracle Database 12c and the Oracle Multitenant option.
January/February 2014 On Oracle Database 12c, Part 3 Our technologist improves partitions, adapts query plans, and optimizes statistics gathering
November/December 2013 On Oracle Database 12c, Part 2 Our technologist finds a match for his SQL and makes his undo temporary.
September/October 2013 On Oracle Database 12c, Part 1 Our technologist improves default values, handles bigger datatypes, and FETCHes for the first time.
July/August 2013 On Randomness, Syntax, and Mutation Our technologist gets deterministic, delimited, and the opposite of trigger-happy.
May/June 2013 On Efficiency, Avoidance, and Performance Our technologist uses brutally efficient DDL, answers trick questions, and suggests a scalar subquery.
March/April 2013 On Becoming Others, Limits, and Restoration Our technologist assumes identities, eliminates external limitations, and recovers constraints.
January/February 2013 On Promotion, Restriction, and Data Loading Our technologist queries missing links, custom sizes, and external table tips.
November/December 2012 On External Table Queries, Data Consistency, and Nothing Our technologist queries the operating system, locks manually, and uses the right NULL.
September/October 2012 On Clustering Factor and Validating Keys Our technologist explains different statistics and very foreign keys.
July/August 2012 On Characters, Pivots, and Endings Our technologist substitutes characters, looks at fishy results, and avoids redo.
May/June 2012 On Connection Pools, Cursor Differentiation, and Optimal Ordering Our technologist cleans pools, explores cursor types, and looks for order in table creation.
March/April 2012 On Unlearning and Modeling Our technologist goes back to school for Oracle Exadata and vows to be a MODEL student.
January/February 2012 On History, Basics, and Network Performance Our technologist recalls a Web seminar, gives the right hint, and dishes on network performance.
November/December 2011 On Collaboration, Testing, When, and Why Our technologist learns from you, is tested on testing, and propagates errors.
September/October 2011 On Caching and Evangelizing SQL Our technologist caches scalar subqueries, votes for SQL, and recommends technology and community.
July/August 2011 On Better Loading and Fact-Checking Our technologist enjoys the rule of external tables and debunks index scan myths.
May/June 2011 On Deferring and Bulking Up Our technologist prefers not to defer and works to increase bulk.
March/April 2011 On Tuning, Planning, and Contexts Our technologist tunes data models, plans for partitions, and puts SQL in context.
January/February 2011 On History, Invisibility, and Moving Our technologist counts on histograms, proves hash tables by example, and moves CLOBs.
November/December 2010 On Consistent Results, Different Constraints, and Unlearning Our technologist reads as of a consistent point in time, uses the right constraint, and revises old learning on unindexed foreign keys.
September/October 2010 On Popularity, Learning, and Unlearning Our technologist revisits a classic, recounts Cardinality Feedback, and remembers SQL*Plus.
July/August 2010 On Connecting, Pivoting, and Learning New Things Our technologist bypasses TNSNAMES .ORA, turns rows to columns, and meets the NO_DATA_FOU ND exception.
May/June 2010 Looking at Edition-Based Redefinition, Part 3 Our technologist concludes his exploration of Edition-Based Redefinition.
March/April 2010 Edition-Based Redefinition, Part 2 Our technologist continues to explore Edition-Based Redefinition, with a full schema change.
January/February 2010 A Closer Look at the New Edition Our technologist redefines and defers with Oracle Database 11g Release 2.
November/December 2009 Looking at the New Edition Our technologist takes a first look at Oracle Database 11g Release 2.
September/October 2009 On DBMS_ROWID, Parsing, and Sizing Our technologist identifies rows, analyzes ratios, and fills space.
July/August 2009 On Popularity and Natural Selection Our technologist optimizes away binds and promotes more-selective queries.
May/June 2009 On Constraints, Metadata, and Truth Our technologist uses constraints to improve query performance.
March/April 2009 On Wrong and Right Our technologist checks the documentation and tests the answers.
January/February 2009 On Dynamic Sampling Our technologist samples dynamically, considers usage, and sets levels.
November/December 2008 On Separation and Counting Our technologist promotes more than one schema, counts partitions, and uses TKPROF.
September/October 2008 The Trouble with Triggers Our technologist looks at trigger maintenance and implementation challenges.
July/August 2008 On Redefinition, Nature, and Triggers Our technologist redefines tables, compares keys, and warns about DDL in triggers.
May/June 2008 On Seeing Double in V$SQL Our technologist looks at SQL repetition in V$SQL and differences in cardinality.
March/April 2008 Oracle Database 11g Redux Our technologist continues to explore Oracle Database 11g features.
January/February 2008 On Tuning by Tracing Our technologist does a tune-up with SQL_TRACE.
November/December 2007 More on Oracle Database 11g Our technologist takes another look at Oracle Database 11g.
September/October 2007 On Oracle Database 11g Our technologist takes a look at the server results and PL/SQL function caches.
July/August 2007 On Ignoring, Locking, and Parsing Our technologist looks out for WHEN OTHERS, locks, cascades, and parses.
May/June 2007 On Loading and Extents Our technologist follows the direct path and optimizes extent usage.
March/April 2007 On Cursors, SQL, and Analytics Our technologist referees between cursors, SQL statements, analytics, and aggregates.
January/February 2007 On Top-n and Pagination Queries Our technologist gets more results using ROW_NUMBER, RANK, and DENSE_RANK.
November/December 2006 On Rescue Analytics and Popularity Our technologist explains the saving power of analytics and shares popularity.
September/October 2006 On ROWNUM and Limiting Results Our technologist explains how ROWNUM works and how to make it work for you.
July/August 2006 On Speeding, Dating, and Spelling Our technologist finds the OS, makes things appear faster, dates clients, and spells out numbers.
May/June 2006 On Joins and Query Plans Our technologist optimizes joins and explains changing plans.
March/April 2006 On Deduping and Ordering Our technologist deletes duplicates, gives trigger orders, and explains how SELECT locks.
January/February 2006 On Sharing, Splitting, and Deleting Our technologist shares cursors, splits large tables, and deletes securely.
November/December 2005 On Transaction Isolation Levels Our technologist isolates transactions safely.

September/October 2005 My First Day with the New Release Our technologist talks about his first experience with Oracle Database 10g Release 2.
July/August 2005 On Searching and Synonyms Our technologist searches, moves, and finds synonyms.
May/June 2005 On Favorites and CONNECT BY Our technologist picks, expands, loads, and dates.
March/April 2005 On Rollups, Merges, and Moves Our technologist materializes, merges, and moves.
January/February 2005 On Injecting and Comparing Our technologist speaks on safe injections, comparing tables, and materialized views.
November/December 2004 On Partitioning and Pipelining Our technologist speaks on UNION ALL, pipelines, and Saturdays.
September/October 2004 On Fetching, Storing, and Indexing Our technologist fetches sequentially, stores inline, and indexes globally.
July/August 2004 On Numbers and Analytics Our technologist searches, numbers, analyzes, and orders.
May/June 2004 On Sorts, Selecting, and Selectivity Our technologist looks at sorting, cursors, architecting, selecting, and extracting.
March/April 2004 On Format, Negation and Sliding Our technologist discusses determining space required, randomizing, and partition outer joins.
January/February 2004 On Uniqueness, Space, and Numbers Our technologist modifies formats, makes zeros zeros, and avoids slides.
November/December 2003 On Constraints, CASE, and Cursors Our technologist talks integrity, time, and belonging.
September/October 2003 On HTML DB, Bulking Up, and Speeding Our technologist looks at Oracle Database 10g's HTML DB, building bulk, and improving speed.
July/August 2003 On Procedures, Flushes, and Writes Our expert compares triggers procedures, flushing, and not flushing.
May/June 2003 On Measuring Distance and Aging Our expert computes distance without aging and highlights favorite Oracle9i features.
March/April 2003 On Partitions, Lookups, and Integrity Our expert partitions, looks up with a PL/SQL table, and does everything with referential integrity.
January/February 2003 On the Explicit, Size, and Complex Our techologist answers questions on cursors, extents, and intervals.
November/December 2002 On Asking, Chaining, and Decoding. Our technologist answers questions about questions, chained rows, and decoding.
September/October 2002 Now Showing and Playing. Our Oracle technologist shows how to use the unused index and how to play.
July/August 2002 Parsing Densities, ANYDATA, and XML. Our technologist looks at the hard parse, the soft parse, and the softer parse.
May/June 2002 On Creating, Dating, and Binding Our technologist creates XML, translates dates, and binds variables.
March/April 2002 Blocks, Messages, Rows A look at block-level information, HTML messages, estimating rows, and AQ.
January/February 2002 Finding Order Our technologist settles the packages-versus-procedures debate.
November/December 2001 Beyond Init.ora and SYS Oracle9i, init.ora, SPFILE, SYS, INTERNAL, and the last row.
September/October 2001 On Different Users, Different Passwords, and Hidden Ability Passwords, undocumented functionality, a different export, and different SGAs.

July/August 2001 Getting What You Want Learn how to get just the rows you want.
May/June 2001 Java, the ESCAPE Sequence, and Synonym Alternatives Serializing Java objects, using ESCAPE with LIKE, communicating return code from SQL*Plus, and using a synonym to view.
March/April 2001 Automation, Cleanup, and Database Maintenance Automatic index maintenance, shows you how to clean up killed sessions faster, and explains differences in Oracle releases.
January/February 2001 Speeding Up, Working Out, and Getting Secure Function-based indexes, SQL, Net8 listener, and user lists.
November/December 2000 Java Tips, JDBC, PL/SQL Stored Procedures, and Custom Prompts Working with Java is simpler now that it's a native part of the Oracle database. Here are some interesting questions I've received about using Java.
September/October 2000 Tips for Migrating, Indexing, and Using Packaged Procedures Looking for advice on upgrading database servers, speeding queries, or avoiding problems with compiling? Our Oracle expert has all the answers.
July/August 2000 Back to Basics With e-initiatives everywhere, DBAs have to ensure robust performance and scalability. Here are some Q&A highlights about sizing tables and pinning a sequence in the SGA.
May/June 2000 Oracle Availability Options Confused about when to implement Oracle Parallel Server (OPS), or replication, or a standby database? Here's an overview of the options.