Difference between revisions of "Storage Layout"

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| 1. Flag for path definition (<code>Boolean</code>, always <code>true</code>; legacy)<br/>2. PathNode:<br/>2.1. Name reference (<code>Num</code>)<br/>2.2. Node kind (<code>Num</code>)<br/>2.3. Number of occurrences (<code>Num</code>)<br/>2.4. Number of children (<code>Num</code>)<br/>2.5. <code>Double</code>; legacy, can be reused or discarded<br/>2.6. Recursive generation of child nodes (→ 2)<code>
 
| 1. Flag for path definition (<code>Boolean</code>, always <code>true</code>; legacy)<br/>2. PathNode:<br/>2.1. Name reference (<code>Num</code>)<br/>2.2. Node kind (<code>Num</code>)<br/>2.3. Number of occurrences (<code>Num</code>)<br/>2.4. Number of children (<code>Num</code>)<br/>2.5. <code>Double</code>; legacy, can be reused or discarded<br/>2.6. Recursive generation of child nodes (→ 2)<code>
 
| valign='top' | [https://github.com/BaseXdb/basex/blob/master/src/main/java/org/basex/index/path/PathSummary.java PathSummary()]<br/>[https://github.com/BaseXdb/basex/blob/master/src/main/java/org/basex/index/path/PathNode.java PathNode()]
 
| valign='top' | [https://github.com/BaseXdb/basex/blob/master/src/main/java/org/basex/index/path/PathSummary.java PathSummary()]<br/>[https://github.com/BaseXdb/basex/blob/master/src/main/java/org/basex/index/path/PathNode.java PathNode()]
 +
|-
 +
| valign='top' | '''2.3. Namespaces'''
 +
| 1. Token set, storing prefixes (<code>TokenSet</code>)<br/>2. Token set, storing URIs (<code>TokenSet</code>)<br/>3. NSNode:<br/>3.1. pre value (<code>Num</code>)<br/>3.2. References to prefix/URI pairs (<code>Nums</code>)<br/>3.3. Number of children (<code>Num</code>)<br/>3.4. Recursive generation of child nodes (→ 3)<code>
 +
| valign='top' | [https://github.com/BaseXdb/basex/blob/master/src/main/java/org/basex/data/Namespaces.java Namespaces()]<br/>[https://github.com/BaseXdb/basex/blob/master/src/main/java/org/basex/data/NSNode.java NSNode()]
 
|}
 
|}

Revision as of 17:53, 26 October 2011

Version: 7.0

Data Types

  • Num: compressed integer (1-5 bytes)
  • Token: length (Num) and bytes of UTF8 byte representation
  • double: number, stored as token
  • boolean: boolean (1 byte, 00 or 01)

inf.basex

Description Format Method
Disk Data Database meta information DiskData()
1. Meta Data Pairs of key/value tokens, suffixed by empty key:
PERM → User Permissions
MetaData.read()
Users.read()
2. Main memory indexes Pairs of key/value tokens, suffixed by empty key:
TAGS → Tag Index
ATTS → Attribute Index
PATH → Path Index
NS → Namespaces
DOCS → Document Index
DiskData()
2.1. Name Index
Element/attribute names
Token set, enriched with statistical information:
1. Token set: key array (Tokens), next/bucket/size arrays (Nums)
2. Content kind (Num)
2.1. Number: min/max (Doubles)
2.2. Category: number of entries (Num), entries (Tokens)
2.3. Number of entries (Num)
2.4. Leaf flag (Boolean)
2.5. Maximum text length (Double; legacy, could be Num)
Names()
TokenSet.read()
StatsKey()
2.2. Path Index 1. Flag for path definition (Boolean, always true; legacy)
2. PathNode:
2.1. Name reference (Num)
2.2. Node kind (Num)
2.3. Number of occurrences (Num)
2.4. Number of children (Num)
2.5. Double; legacy, can be reused or discarded
2.6. Recursive generation of child nodes (→ 2)
PathSummary()
PathNode()
2.3. Namespaces 1. Token set, storing prefixes (TokenSet)
2. Token set, storing URIs (TokenSet)
3. NSNode:
3.1. pre value (Num)
3.2. References to prefix/URI pairs (Nums)
3.3. Number of children (Num)
3.4. Recursive generation of child nodes (→ 3)
Namespaces()
NSNode()