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From Alexander Paschenko <alexander.a.pasche...@gmail.com>
Subject Re: Ignite SQL: How to drop table without explicit cache name
Date Fri, 02 Feb 2018 21:19:08 GMT
Guys,

Right, first option is the way to go. Options 2 and 3 are surrogates
that do not free you from concept of cache but rather allow you to
obtain one.

I believe in near future we'll propose public API for cacheless queries.

- Alex

2018-02-01 19:38 GMT+03:00 Valentin Kulichenko <valentin.kulichenko@gmail.com>:
> Nikolay,
>
> I believe the first option is the way to go. However, I'd also like to hear
> from other community members.
>
> Vladimir, Alex P, can you comment on this? I know we currently don't have
> public API to execute DDL statement without having a cache. However, looks
> like we use private API of GridQueryProcessor to overcome this in JDBC
> drivers and Web Console. We now need a similar solution for data frames
> integration, can you confirm that we're moving in the right direction?
>
> -Val
>
> On Thu, Feb 1, 2018 at 4:04 AM, Nikolay Izhikov <nizhikov@apache.org> wrote:
>
>> Hello, guys.
>>
>> I working on support of saving Spark DataFrame to Ignite [1].
>>
>> I want to execute "DROP TABLE XXX" query.
>> To execute some SQL query in regulary way one need some cache.
>> That cache has to differs from table cache to execute "DROP TABLE"
>> successfully.
>>
>> I founded 3 different ways to execute SQL query without explicit cache
>> name.
>> Please, tell me which way is right?
>> Do we need all 3 way to make a query?
>>
>> 1. JdbcRequestHandler - [2]
>>
>> ```
>>
>>     private final GridKernalContext ctx;
>> ...
>>     List<FieldsQueryCursor<List<?>>> results = ctx.query().querySqlFields(qry,
>> true, protocolVer.compareTo(VER_2_3_0) < 0);
>>
>> ```
>>
>> 2. GridCacheProcessor - [3]
>>
>> ```
>>
>>     /**
>>     * Gets public cache that can be used for query execution.
>>     * If cache isn't created on current node it will be started.
>>     */
>>     public IgniteCacheProxy<?, ?> getOrStartPublicCache(boolean start,
>> boolean inclLoc) throws IgniteCheckedException {
>>
>> ```
>>
>> 3. QueryCommandHandler - [4]
>>
>> ```
>>
>>         protected static final String DFLT_CACHE_NAME = "default";
>> ...
>>         String cacheName = req.cacheName() == null ? DFLT_CACHE_NAME :
>> req.cacheName();
>>
>> ```
>>
>>
>> [1] https://issues.apache.org/jira/browse/IGNITE-7337
>> [2] https://github.com/apache/ignite/blob/master/modules/
>> core/src/main/java/org/apache/ignite/internal/processors/
>> odbc/jdbc/JdbcRequestHandler.java#L310
>> [3] https://github.com/apache/ignite/blob/master/modules/
>> core/src/main/java/org/apache/ignite/internal/processors/
>> cache/GridCacheProcessor.java#L1648
>> [4] https://github.com/apache/ignite/blob/master/modules/
>> core/src/main/java/org/apache/ignite/internal/processors/
>> rest/handlers/query/QueryCommandHandler.java#L318

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