Changes

==Data Types==* <code>Num</code>: compressed integer (1This article is part of the [[Advanced User's Guide]]. It presents some low-5 bytes)* <code>Token</code>: length (<code>Num</code>) and bytes of UTF8 byte representation* <code>double</code>: number, level details on how data is stored as token* <code>boolean</code>: boolean (1 byte, <code>00</code> or <code>01</code>)in the database files.

==inf.basex=Data Types=

The following data types are used for specifying the storage layout: {| class="wikitable" width|- valign="top"! Type! Description! Example (native → hex integers)|- valign="100%top"| {{Type|Num}}| Compressed integer (1-5 bytes), specified in [https://github.com/BaseXdb/basex/blob/master/basex-core/src/main/java/org/basex/util/Num.java Num.java]| {{Code|15}} → {{Code|0F}}; {{Code|511}} → {{Code|41 FF}}<br/>|-valign="top"| {{Type|Token}}| Length ({{Type|Num}}) and bytes of UTF8 byte representation| {{Code|Hello}} → {{Code|05 48 65 6c 6c 6f}}|- valign="top"| {{Type|Double}}| Number, stored as token| {{Code|123}} → {{Code|03 31 32 33}}|- valign="top"| {{Type|Boolean}}| Boolean (1 byte, {{Code|00}} or {{Code|01}})| {{Code|true}} → {{Code|01}}|- valign="top"| {{Type|Nums}}, {{Type|Tokens}}, {{Type|Doubles}}| Arrays of values, introduced with the number of entries| {{Code|1,2}} → {{Code|02 01 31 01 32}}|- valign="top"| {{Type|TokenSet}}| Key array ({{Type|Tokens}}), next/bucket/size arrays (3x {{Type|Nums}})||} =Database Files= The following tables illustrate the layout of the BaseX database files. All files are suffixed with {{Code|.basex}}. ==Metadata, Name/Path/Doc Indexes: {{Code|inf}}== {| class="wikitable"|- valign="top"

! Method|-| valign='"top' | '''Disk Data'''"| Database meta information| valign='top' | [https://github.com/BaseXdb/basex/blob/master/src/main/java/org/basex/data/DiskData.java DiskData()]|-| valign='top' | '''1. Meta DataMetadata'''| Pairs of key1. Key/value tokenspairs, suffixed by empty keyin no particular order ({{Type|Token}}/{{Type|Token}}):<br />&nbsp; &bull; Examples: {{Code|FNAME}}, {{Code|TIME}}, {{Code|SIZE}}, ...<codebr/>&nbsp; &bull; {{Code|PERM</code> }} → User PermissionsNumber of users ({{Type| valign='top' | [https:Num}}), and name/password/github.compermission values for each user ({{Type|Token}}/BaseXdb{{Type|Token}}/basex/blob/master/src/main/java/org/basex/data/MetaData.java MetaData.read({{Type|Num}})]<br/>[https://github2.com/BaseXdb/basex/blob/master/src/main/java/org/basex/core/Users.java Users.read()]Empty key as finalizer|-| valign='"top' "| '''2. Main memory indexes'''| Pairs of key1. Key/value tokenspairs, suffixed by empty keyin no particular order ({{Type|Token}}/{{Type|Token}}):<br />&nbsp; &bull; <code>{{Code|TAGS</code> }} → Tag Element Name Index<br />&nbsp; &bull; <code>{{Code|ATTS</code> }} → Attribute Name Index<br />&nbsp; &bull; <code>{{Code|PATH</code> }} → Path Index<br />&nbsp; &bull; <code>{{Code|NS</code> }} → Namespaces<br />&nbsp; &bull; <code>{{Code|DOCS</code> }} → Document Index| valign='top' | [https:<br//github>2.com/BaseXdb/basex/blob/master/src/main/java/org/basex/data/DiskData.java DiskData()]Empty key as finalizer|-| valign='"top' "| '''2.1. a) Name Index'''<br/>Element/attribute names| 1. Token set, enrichted with statistical information:storing all names ({{Type|TokenSet}})<br />12. Token setOne StatsKey instance per entry: key array (<code>Tokens</code>), next/bucket/size arrays (<code>Nums</code>)<br />2.1. Content kind (<code>{{Type|Num</code>}}):<br />2.1 .1. Number: min/max (<code>{{Type|Doubles</code>}})<br />2.1.2. Category: number of entries (<code>{{Type|Num</code>}}), entries (<code>{{Type|Tokens</code>}})<br />2.3 2. Number of entries (<code>{{Type|Num}})<br/code>2.3. Leaf flag ({{Type|Boolean}})<br />2.4 Leaf flag . Maximum text length ({{Type|Double}}; legacy, could be {{Type|Num}})|- valign="top"| '''2 b) Path Index'''| 1. Flag for path definition ({{Type|Boolean}}, always {{Code|true}}; legacy)<codebr/>Boolean2. PathNode:<br/>2.1. Name reference ({{Type|Num}})<br/code>2.2. Node kind ({{Type|Num}})<br />2.5 Maximum text length 3. Number of occurrences ({{Type|Num}})<codebr/>Double2.4. Number of children ({{Type|Num}})<br/code>2.5. {{Type|Double}}; legacy, could can be reused or discarded<code>Num<br/code>2.6. Recursive generation of child nodes (→ 2)| - valign="top"| '''2 c) Namespaces''top' | [https://github1.comToken set, storing prefixes ({{Type|TokenSet}})<br/BaseXdb/basex/blob/master/src/main/java/org/basex/index/Names>2.java NamesToken set, storing URIs ({{Type|TokenSet}})]<br/>[https3. NSNode:<br/>3.1. pre value ({{Type|Num}})<br/github>3.com2. References to prefix/BaseXdbURI pairs ({{Type|Nums}})<br/basex/blob/master/src/main/java/org/basex/util/hash/TokenSet>3.3.java TokenSetNumber of children ({{Type|Num}})]<br/>[https://github3.com/BaseXdb/basex/blob/master/src/main/java/org/basex/index/StatsKey4.java StatsKeyRecursive generation of child nodes (→ 3)]|-| valign='"top' "| '''2.2. Path d) Document Index'''| Array of integers, representing the distances between all document pre values ({{Type|Nums}})