Table: `ndb.relativechronology`#

Description#

This table stores relative chronologic data. Relative Ages are assigned to Analysis Units, The Relative Age data along with any possible Geochronology and Tephrachronology data are used to create a chronology.

TODO: Expand this description with: - What data does this table store? - What is the business/research purpose? - How is this data collected or generated? - Are there any important caveats or data quality issues?

Table Structure#

Schema: ndb | Table Comment: This table stores relative chronologic data. Relative Ages are assigned to Analysis Units, The Relative Age data along with any possible Geochronology and Tephrachronology data are used to create a chronology.

Statistics#

Metric	Value
Row Count	4,631
Total Size	1704 kB
Table Size	312 kB
Indexes Size	1384 kB

Relationships#

Primary Key: relativechronid

Foreign Keys:

analysisunitid → analysisunits.analysisunitid
relativeageid → relativeages.relativeageid
chroncontrolid → chroncontrols.chroncontrolid

Referenced By:

TODO: Document which tables reference this table (will be auto-detected in validation).

Data Dictionary#

Column	Type	Nullable	Default	Constraints	Description
`relativechronid`	integer	✗	`nextval('ndb.seq_relativech...`	PRIMARY KEY	An arbitrary Relative Chronology identification number.
`analysisunitid`	integer	✗	`-`	FOREIGN KEY	Analysis Unit identification number. Field links to the AnalysisUnits table.
`relativeageid`	integer	✗	`-`	FOREIGN KEY	Relative Age identification number. Field links to the RelativeAges lookup table.
`notes`	text	✓	`-`	-	Free form notes or comments.
`recdatecreated`	timestamp without time zone	✗	`timezone('UTC'::text, now())`	-
`recdatemodified`	timestamp without time zone	✗	`-`	-
`chroncontrolid`	integer	✓	`-`	FOREIGN KEY

TODO: Review column descriptions and add comments where missing.

Usage Examples#

Example 1: Basic Selection#

-- Get recent records from relativechronology
SELECT *
FROM relativechronology
ORDER BY relativechronid DESC
LIMIT 10;

Purpose: Retrieve the 10 most recent records from relativechronology

Example 2: Count Records#

-- Count total records
SELECT COUNT(*) as total_records
FROM relativechronology;

Purpose: Get the total number of records in relativechronology

Example 3: Filter by Date Range#

-- Get records within a date range
SELECT *
FROM relativechronology
WHERE recdatecreated >= '2024-01-01'
  AND recdatecreated < '2025-01-01'
ORDER BY recdatecreated DESC;

Purpose: Retrieve records from relativechronology within a specific date range

Example 4: Join with analysisunits#

-- Join with related table
SELECT 
    t1.*,
    t2.*
FROM relativechronology t1
INNER JOIN analysisunits t2 
    ON t1.analysisunitid = t2.analysisunitid
LIMIT 100;

Purpose: Retrieve relativechronology records with related data from analysisunits

Example 5: Aggregate Data#

-- Aggregate records by analysisunitid
SELECT 
    analysisunitid,
    COUNT(*) as count
FROM relativechronology
GROUP BY analysisunitid
ORDER BY count DESC
LIMIT 10;

Purpose: Count records grouped by analysisunitid

TODO: Add more specific examples relevant to common research questions or operational tasks.

Data Quality Notes#

TODO: Document: - Known data quality issues - Validation rules - Expected data ranges - Update frequency and mechanisms - Any ETL processes that populate this table

Maintenance#

Data Owner: TODO: Assign owner
Update Frequency: TODO: Document frequency
Last Major Schema Change: TODO: Document when schema last changed

Table: ndb.relativechronology#