Category: Programming

Oracle, index-organized tables, and overflow tablespaces

SQL Error: ORA-25191: cannot reference overflow table of an index-organized table

A refresher: a SQL database is relational, and rows are stored unsorted; Oracle calls standard tables heap-organized tables. For a given SQL query, unless an ORDER BY clause is used, results can be returned in any order. Oracle also has IOTs, which are tables that are instead stored in a B*Tree index structure. This structure stores all columns of the table, sorted by primary key; because this is both the table and the index, accessing rows is much faster and less storage space is needed than for a heap-organized table with a separate index.

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Comma placement in sql scripts

It’s a truism that old habits are hard to break. Turn down the same street every day, and you’d better pay attention if you want to actually make it past that intersection without turning! One habit I feel that I...

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Interfaces in C#

Consider test-driving a new car, of a make and model you’re not familiar with. It’s unlikely you’ll need any instruction in how to do it: rightmost pedal makes the car go, pedal next to it makes the car stop....

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When not to optimize

Software development has some consistent goals. We want the software to be as fast as possible, as small as possible, to work as well as possible, and to be done as soon as possible. Naturally there tend to be trade-offs between...

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