Data Integrity and Storage

provides several capabilities to check on the quality of data on a node and to quarantine segment groups that are problematic for any reason also, you can manage pages by converting them to segments related to data integrity is the ability to rebuild tasks for details, see distributed tasks docid\ nzcumjzl9xke v0x8uxho alter segment quarantine alter segment quarantine isolates segment groups from segment generation or queries use this sql statement if segments are causing unexpected results or crashes the segments can be un quarantined by setting quarantine level to none syntax \ to quarantine a single segment group alter segment quarantine for { \<quarantine level> } where segment group id = seg id \ to quarantine multiple segment groups alter segment quarantine for { \<quarantine level> } where segment group id in ( seg id \[, ] ) \<quarantine level> = segment generation | query | all | none parameter data type description seg id numeric the identification numbers for segment groups depending on your alter segment quarantine statement, the ocient system quarantines the specified segment groups for having an existing quarantine removed for details about finding abnormal segments, see the guide to rebuilding segments docid\ k7yexxwh7npsrmkcze8 b using quarantine levels ( \<quarantine level> ) you can place quarantines at these segment levels level description segment generation isolates the specified segments from segment generation this statement prevents corrupt data from causing problems while still leaving the data available for future analysis query isolates segment groups from subsequent queries data that is quarantined at the query level is not returned by database queries this can be useful to prevent corrupt data from causing query problems while leaving it available for future analysis all isolates the specified segments from segment generation and subsequent queries none removes any quarantines from the specified segments examples this example quarantines a single segment group from segment generation alter segment quarantine for segment generation where segment group id = 123456789; this example quarantines multiple segment groups from segment generation alter segment quarantine for segment generation where segment group id in (1,2,3,4,5); this example removes a quarantine from a single segment group alter segment quarantine for none where segment group id = 123456789; this example removes a quarantine from multiple segment groups alter segment quarantine for none where segment group id in (1,2,3,4,5); this example quarantines at the query level alter segment quarantine for query where segment group id = 123456789; this example removes a quarantine at the query level alter segment quarantine for none where segment group id = 123456789; this example quarantines at both the query and segment group levels alter segment quarantine for all where segment group id = 123456789; drain pages the drain pages sql statement instructs the ocient system to immediately convert buffered pages into segments on one or more loader nodes during normal operation, the system converts pages to segments automatically based on internal thresholds and timeouts, so the drain pages statement is usually needed only in special circumstances for example, draining pages can be useful before performing planned maintenance on loader nodes the sql statement targets all loader nodes by default you can optionally scope the operation to a specific storage scope or table, and you can restrict it to a subset of loader nodes the drain pages statement forces the immediate restructuring of buffered data into durable segments, which can affect system resource utilization and loading performance contact ocient support before using this sql statement required privileges to drain all pages or drain pages for a specific storage scope, you must have update privileges on the system to drain pages for a specific table, you must have update privileges on the system or delete privileges on the database that contains the table syntax drain pages \[ for { scope uuid = scope uuid \| table uuid = table uuid } ] \[ with loaders loader name \[, loader name \[, ] ] ] parameter type description scope uuid string the universally unique identifier (uuid) of a storage scope when you specify this value, the system converts only pages that belong to this storage scope this value is mutually exclusive with the table uuid value to find storage scope uuids, query the sys storage scopes docid\ fg0berygjpzqfr7dp pqv system catalog table table uuid string the uuid of a table when you specify this value, the system converts only pages that belong to this table this value is mutually exclusive with the scope uuid value to find table uuids, query the sys tables docid\ fg0berygjpzqfr7dp pqv system catalog table loader name string the name of a loader node when you specify one or more loader names, the system sends the drain request only to those nodes by default, the system sends the request to all loader nodes examples drain all pages this example converts all buffered pages to segments across every loader node drain pages; drain pages for a storage scope this example converts only pages associated with the storage scope identified by the uuid a1b2c3d4 e5f6 7890 abcd ef1234567890 drain pages for scope uuid = 'a1b2c3d4 e5f6 7890 abcd ef1234567890'; drain pages for a table this example converts only pages associated with the table identified by the uuid 12345678 abcd ef01 2345 6789abcdef01 drain pages for table uuid = '12345678 abcd ef01 2345 6789abcdef01'; drain pages on specific loader nodes this example sends the drain request to the loader node 1 and loader node 2 loader nodes drain pages with loaders 'loader node 1', 'loader node 2'; drain pages for a table on a specific loader node this example converts only pages associated with the table identified by the uuid 12345678 abcd ef01 2345 6789abcdef01 on the loader node 1 loader node drain pages for table uuid = '12345678 abcd ef01 2345 6789abcdef01' with loaders 'loader node 1'; related links errors and warnings docid\ jdioanniixa8vjzdvey1c