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To process this statement without an index the database software must look at the last_name column on every row in the table (this is known as a full table scan). With an index the database simply follows the index data structure (typically a B-tree ) until the Smith entry has been found; this is much less computationally expensive than a full ...
This allows indexes to be defined for common query conditions that depend on data in a table, but are not actually stored in that table. A common use for an expression index is to support case-insensitive searching or constraints. For example, if a web site wants to make user names case-insensitive, but still preserve the case as originally ...
There are several advanced scrolling tables (with row and column headers that stay visible and sticky while scrolling) in COVID-19 pandemic by country and territory and in COVID-19 pandemic deaths. The scrolling and sticky headers work in cell phones, too. Widest scrolling tables are on top of the list below.
The table above (even if some more columns are added) maintains one line per country for narrower browser and screen widths. So it is therefore more readable and scannable in long country tables. The table format below can greatly increase in number of lines, and require more vertical scrolling, especially if more columns are added.
While some special software packages exist, to allow customized editing, they are typically not available when travelling to other computers for wiki-editing. Some techniques here are beyond the basics described in the Wikipedia help-page "Help:Table" which explains almost all basic options of table formatting, also showing examples of each.
Database tables and indexes may be stored on disk in one of a number of forms, including ordered/unordered flat files, ISAM, heap files, hash buckets, or B+ trees. Each form has its own particular advantages and disadvantages. The most commonly used forms are B-trees and ISAM.
Click "number format" from the format menu. Then click "thousands separator" from the submenu. Then click "thousands separator" from the submenu. This will add commas or periods depending on the default language you have selected in Calc for the locale setting.
Python sets are very much like mathematical sets, and support operations like set intersection and union. Python also features a frozenset class for immutable sets, see Collection types. Dictionaries (class dict) are mutable mappings tying keys and corresponding values. Python has special syntax to create dictionaries ({key: value})