io.questdb.cairo.sql.PageFrame Maven / Gradle / Ivy
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*
* Copyright (c) 2014-2019 Appsicle
* Copyright (c) 2019-2020 QuestDB
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
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package io.questdb.cairo.sql;
public interface PageFrame {
// todo: implement for TablePageFrameCursor
default long getFirstTimestamp() {
throw new UnsupportedOperationException();
}
/**
* Return the address of the start of the page frame or if this page represents
* a column top (a column that was added to the table when other columns already had data) then return 0
*
* @param columnIndex index of column
* @return address of column or 0 if column is empty
*/
long getPageAddress(int columnIndex);
/**
* Return the size of the page frame or if the page represents a column top
* (a column that was added to the table when other columns already had data),
* then return the number of of empty rows at the top of a column
*
* @param columnIndex index of column
* @return size of page in bytes
*/
long getPageSize(int columnIndex);
}