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Table |
A table involved in the operation. |
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Table eligible for synchronized scanning (not cached) |
A table involved in the operation that is eligible for synchronized scanning. |
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Spool |
A spool, which is where intermediate query results are stored. |
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Low Confidence Spool |
A target spool, where the number of rows is estimated with a low confidence. |
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High Confidence Spool |
A target spool, where the number of rows is estimated with a high confidence. |
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Index Join Confidence Spool |
A target spool, where the number of rows is estimated with an index join confidence. |
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No Confidence Spool |
A target spool, where number of rows is estimated with no confidence, which may indicate lack of collected statistics or certain query constraints. |
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High Confidence IN-List Spool |
A spool whose rows are made up from the values of an IN condition. Used to maximize the performance of a special class of star join queries. The confidence is always high because the cardinality is known. |