I'd rather play golf

One of my personal highlights in attending last week’s ACM SIGMOD 2011 conference in Athens was to take in a tutorial [1] on Thursday morning entitled Data Management Over Flash Memory, presented by Ioannis Koltsidas of IBM Zurich and Stratis Viglas of the University of Edinburgh. Here was the abstract: Flash SSDs are quickly becoming [...]

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SQL Anywhere has offered autonomic, self-managing statistics collection since 1992 [1]. In SQL Anywhere 12, we are going one step further with the introduction of a “statistics governor” that makes SQL Anywhere column histograms both self-monitoring and self-healing. Self-healing statistics management in SQL Anywhere 12 includes the: recording and categorization of selectivity estimation errors in [...]

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Yesterday afternoon I listened to Sunil Prabhakar of Purdue University on the Orion Uncertain Data Management System [1-4]. Sunil’s talk is one of the Database Seminar Series at the University of Waterloo which is sponsored by Sybase iAnywhere. Here’s Sunil’s abstract: Many applications domains are faced with the need to store and manipulate uncertain or [...]

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Yesterday afternoon I listened to Sunil Prabhakar of Purdue University on the Orion Uncertain Data Management System [1-4]. Sunil’s talk is one of the Database Seminar Series at the University of Waterloo which is sponsored by Sybase iAnywhere. Here’s Sunil’s abstract: Many applications domains are faced with the need to store and manipulate uncertain or [...]

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Despite our efforts at making relational database systems such as SQL Anywhere self-managing, self-tuning, and self-healing, there remains the need to be able to diagnose and repair performance problems. In part, this requirement is due to the overall complexity of the optimization task. Query optimization is – still – an NP-hard problem and the input [...]

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Starting with Version 10, SQL Anywhere supports deferred-maintenance materialized views; version 11 introduced support for immediately-maintained materialized views. The major differences between the two are: With deferred-maintenance materialized views, the query optimizer may answer queries utilizing one or more materialized views that contain stale data. The “staleness” of any view, and whether or not the [...]

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At June’s 2009 ACM SIGMOD Conference, Surajit Chaudhuri of Microsoft Research presented a thought-provoking paper [1] entitled “Query Optimizers: Time to Rethink the Contract?”. Here is the abstract: Query Optimization is expected to produce good execution plans for complex queries while taking relatively small optimization time. Moreover, it is expected to pick the execution plans [...]

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SQL Anywhere version 11.0.0 introduced support for search conditions that include regular expression searching. There are two variants of regular expression search predicates that one can use, each with their own semantics: SIMILAR TO and REGEXP. SIMILAR TO The SIMILAR TO predicate is part of the 2008 ANSI/ISO SQL standard. However, the draft of the [...]

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In an earlier post on SQL request hints, I described techniques to modify concurrency control semantics with a specific SQL statement. In this second post, I’d like to describe some additional hinting capabilities supported by SQL Anywhere with respect to query optimization. Just to be clear once again, I’m not advocating the use of hints. [...]

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ACM SIGMOD 2009 is being held in Providence, Rhode Island from June 29 through July 2. The conference program is online and this year’s sessions look particularly interesting. Alas I will not, unfortunately, be able to attend. However, Anil Goel and Ani Nica of my staff will be at SIGMOD. In particular, Ani will be [...]

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