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https://issues.apache.org/jira/browse/PHOENIX-4227?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16178294#comment-16178294
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Karan Mehta commented on PHOENIX-4227:
--------------------------------------
I am referring to {{ConnectionQueryServicesImpl#init(String url, Properties
props)}} method, which first checks if SYSTEM tables are upgraded with the
method {{ensureSystemTablesUpgraded()}}, which inturn checks if SYSTEM
namespace is created or not by calling the method
{{ensureNamespaceCreated(String schemaName)}}. This method directly creates a
HBase namespace with the HBase API, thus bypassing its entry in the
{{SYSTEM.CATALOG}} table.
Here is the relevant piece of code.
{code}
try (HBaseAdmin admin = getAdmin()) {
NamespaceDescriptor namespaceDescriptor = null;
try {
namespaceDescriptor = admin.getNamespaceDescriptor(schemaName);
} catch (org.apache.hadoop.hbase.NamespaceNotFoundException e) {
}
if (namespaceDescriptor == null) {
namespaceDescriptor =
NamespaceDescriptor.create(schemaName).build();
admin.createNamespace(namespaceDescriptor);
}
return;
} catch (IOException e) {
sqlE = ServerUtil.parseServerException(e);
} finally {
if (sqlE != null) { throw sqlE; }
}
{code}
I added the method in
{{SystemTablePermissionsIT#testNamespaceMappedSystemTables() }} test to read
SYSCAT. However I found that row missing. After executing the statement
{{CREATE SCHEMA IF NOT EXISTS SYSTEM}}, the row was created in SYSCAT.
{code}
private void readTable(String tableName) throws SQLException, IOException {
System.out.println("Reading table: " + tableName);
try (Connection conn = DriverManager.getConnection(getJdbcUrl(),
clientProperties);) {
HTable table = (HTable)
conn.unwrap(PhoenixConnection.class).getQueryServices().getTable(tableName.getBytes());
Scan scan = new Scan();
ResultScanner results = table.getScanner(scan);
Result result = results.next();
while(result != null) {
System.out.println("TableName = " +
Bytes.toString(result.getRow()));
NavigableMap<byte[], NavigableMap<byte[], NavigableMap<Long,
byte[]>>> map = result.getMap();
for(Map.Entry<byte[], NavigableMap<byte[], NavigableMap<Long,
byte[]>>> entry : map.entrySet()) {
for(Map.Entry<byte[], NavigableMap<Long, byte[]>> entry1 :
entry.getValue().entrySet()) {
System.out.println("\tentry1.getKey() = " +
Bytes.toString(entry1.getKey()));
for(Map.Entry<Long, byte[]> entry2 :
entry1.getValue().entrySet()) {
System.out.println("\t\tentry2.getValue() = " +
Bytes.toString(entry2.getValue()));
}
}
}
result = results.next();
}
}
System.out.println("End of reading");
}
{code}
This init method is used by PhoenixDriver and PhoenixEmbeddedDriver, connect()
method.
> Row for "SYSTEM" schema is not created during ConnectionQueryServicesImpl
> init
> -------------------------------------------------------------------------------
>
> Key: PHOENIX-4227
> URL: https://issues.apache.org/jira/browse/PHOENIX-4227
> Project: Phoenix
> Issue Type: Bug
> Affects Versions: 4.12.0
> Reporter: Karan Mehta
>
> For every new schema created through Phoenix, a row containing the schema
> name (with a 0x0 at the beginning and the end) is added to SYSTEM.CATALOG
> table. This is used for by other statements such as "USE SCHEMA" or "CREATE
> SCHEMA" to determine if the schema exists or not.
> However when we turn on namespaces, SYSTEM tables are automatically migrated
> to SYSTEM namespace in HBase. However an SYSTEM.CATALOG entry with the row
> (\x0SYSTEM\x0) is not created. Thus other statements trying to use it might
> receive a SCHEMA_NOT_FOUND_EXCEPTION even though the schema exists in the
> file.
> A "CREATE SCHEMA SYSTEM" statement can create the corresponding row entry in
> the SYSCAT table. This JIRA is to fix this behaviour and make it consistent
> for all schemas across Phoenix.
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