THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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The table below documents the execution capability in specific modules of MetaModel. Each column represents a query type. The query types are:
- Plain FROM:
- Simple queries of the form '
SELECT y FROM x
'. Possible values: - streaming: The dataset is implemented in a truly streaming fashion.
- paged: The dataset fetches pages/bulks of records.
- in-memory: The dataset has to consume ALL records into memory. This is ineffecient and may cause out of memory issues.
- Simple queries of the form '
- Simple COUNT:
- Queries of the form '
SELECT COUNT(*) FROM x
'. Possible values: - native: The module supports a effective native method of getting the count. Some modules also support additional criteria on COUNT queries, e.g. '
SELECT COUNT(*) FROM x WHERE z
' which is marked as 'native (incl. WHERE)'. - greedy: The module has to run through the dataset to do the counting. This is ineffecient but usually has little memory impact.
- Queries of the form '
- Simple WHERE:
- Are simple WHERE items being delegated natively, or are they evaluated client-side for each record?
- Primary key lookup:
- Queries that look up records by their primary keys:
SELECT y FROM x WHERE x.id = 42
.
- Queries that look up records by their primary keys:
- Groups and aggregates:
- Are GROUP BY and aggregation functions being delegated natively, or are they calculated in memory?
Plain FROM | Simple COUNT | Simple WHERE | Primary key lookup | Groups and aggregates | ||
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CSV |
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JDBC | ||||||
Excel |
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POJO | ||||||
Apache CouchDB | ||||||
MongoDB | ||||||
ElasticSearch | ||||||
Apache HBase | ||||||
Apache Cassandra | ||||||
Apache Kafka |
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Amazon DynamoDB | | |||||
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JSON | |||||
XML |
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Salesforce.com | |||||
SugarCRM |