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| <meta name="DC.Title" content="PARQUET_READ_PAGE_INDEX Query Option" /> |
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| <title>PARQUET_READ_PAGE_INDEX Query Option</title> |
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| <body id="parquet_read_page_index"> |
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| <h1 class="title topictitle1" id="ariaid-title1">PARQUET_READ_PAGE_INDEX Query Option</h1> |
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| <p class="p"> |
| Use the <code class="ph codeph">PARQUET_READ_PAGE_INDEX</code> query option to disable or enable using |
| the Parquet page index during scans. The page index contains min/max statistics at the |
| page-level granularity. It can be used to skip pages and rows that do not match the |
| conditions in the <code class="ph codeph">WHERE</code> clause. |
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| This option enables the same optimization as the <code class="ph codeph">PARQUET_READ_STATISTICS</code> |
| at the finer grained page level. |
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| Impala supports filtering based on Parquet statistics: |
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| Of the types: Boolean, Integer, Decimal, String, Timestamp |
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| For simple predicates of the forms: <code class="ph codeph"><slot> <op> <constant></code> or |
| <code class="ph codeph"><constant> <op> <slot></code>, where <code class="ph codeph"><op></code> is LT, |
| LE, GE, GT, and EQ |
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| </ul> |
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| The supported values for the query option are: |
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| <code class="ph codeph">true</code> (<code class="ph codeph">1</code>): Read the page-level statistics from the |
| Parquet page index during query processing and filter out pages based on the |
| statistics. |
| </li> |
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| <li class="li"> |
| <code class="ph codeph">false</code> (<code class="ph codeph">0</code>): Do not use the Parquet page index. |
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| Any other values are treated as <code class="ph codeph">false</code>. |
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| <p class="p"> |
| <strong class="ph b">Type:</strong> Boolean |
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| <strong class="ph b">Default:</strong> <code class="ph codeph">TRUE</code> |
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| <div class="related-links"> |
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| <div class="parentlink"><strong>Parent topic:</strong> <a class="link" href="../topics/impala_set.html">SET Statement</a></div> |
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