/*
*
* SchemaCrawler
* http://sourceforge.net/projects/schemacrawler
* Copyright (c) 2000-2013, Sualeh Fatehi.
*
* This library is free software; you can redistribute it and/or modify it under the terms
* of the GNU Lesser General Public License as published by the Free Software Foundation;
* either version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
*/
package schemacrawler.tools.linter;
import static schemacrawler.tools.lint.LintUtility.columns;
import static schemacrawler.tools.lint.LintUtility.listStartsWith;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import schemacrawler.schema.Index;
import schemacrawler.schema.Table;
import schemacrawler.schema.View;
import schemacrawler.tools.lint.BaseLinter;
import schemacrawler.tools.lint.LintSeverity;
public class LinterRedundantIndices
extends BaseLinter
{
public LinterRedundantIndices()
{
setSeverity(LintSeverity.high);
}
@Override
public String getDescription()
{
return getSummary();
}
@Override
public String getSummary()
{
return "redundant index";
}
@Override
protected void lint(final Table table)
{
if (table != null && !(table instanceof View))
{
final Collection<Index> indices = table.getIndices();
if (indices.size() > 0)
{
final Set<Index> redundantIndices = findRedundantIndices(indices);
for (final Index index: redundantIndices)
{
addLint(table, getSummary(), index);
}
}
}
}
private Set<Index> findRedundantIndices(final Collection<Index> indices)
{
final Set<Index> redundantIndices = new HashSet<>();
final Map<Index, List<String>> indexColumns = new HashMap<>(indices
.size());
for (final Index index: indices)
{
indexColumns.put(index, columns(index));
}
for (final Entry<Index, List<String>> indexColumnEntry1: indexColumns
.entrySet())
{
for (final Entry<Index, List<String>> indexColumnEntry2: indexColumns
.entrySet())
{
if (!indexColumnEntry1.equals(indexColumnEntry2))
{
if (listStartsWith(indexColumnEntry1.getValue(),
indexColumnEntry2.getValue()))
{
redundantIndices.add(indexColumnEntry2.getKey());
}
}
}
}
return redundantIndices;
}
}