Use case
ClickHouse/ClickHouse#7971

数据源对接jdbc presto,presto sql不复杂，但一个任务对接多个看板，返回数据 是null,查看 代码:
synchronized (context) {
context.wait(10 * 60 * 1000);
}
唤醒代码：
synchronized (context) {
context.setData(data);
context.notify();
}
返回的data=null,
我将自动等待时长加到30 * 60 * 1000，错误还是一样

None of the classes hyperlinks lead to the class doxygen class documentation.

When specifying a model, if I add some attributes that don't exist in my dataset I get no warnings or errors. To reproduce, you can use the sample model.json file in examples/hello_world folder:

            "mappings": {
                        "item.line_item": "line_item",
                        "item.subcategory": "subcategory",
                        "item.subcategory_label": "s

Add xa admin commands:

1. radon xa recover

mysql > radon xa recover;
+----------+--------------+
| formatID | backend |
+----------+--------------+
|     xxx |   xx          |
+----------+--------------+
1 row in set (0.00 sec)

2. radon xa rollback all;
   rollback all the xa transaction

3. radon xa commit all;
   commit all the xa transaction

Merging a few issues into one here.

Numeric Scalar

• ACOS, ASIN, ATAN, COS, SIN, TAN, COT, ATAN2 [MySQL, PostgreSQL]
• BIT_AND, BIT_COUNT, BIT_LENGTH, BIT_OR, BIT_XOR, ~ [MySQL]
• CEIL, CEILING, FLOOR [MySQL, PostgreSQL]
• LOG, LOG10, LOG2, LN [MySQL, PostgreSQL]
• PI [PostgreSQL]
• RANDOM
• SQRT, POWER, CBRT [PostgreSQL]

https://www.postgresql.org/docs/8

Please include a tutorial on how to set up Connections, Cubes, Schedulers, etc., including steps on how to troubleshoot any connection problems in particular.

Thanks for help.
I find the doucment for mondrian 4 schema (https://mondrian.pentaho.com/head/documentation/schema.php#Schema_element), but the very import chapters (3.3) missing, and i cannot find any infromation about Dimensions key and Attributes. Its so different about mondrian 3. So where i can find some useful information about it. I search it in google but nothing helpful.

From #100, negative values are not shown by the pie chart.

Possibilities:

1. At least inform the user that N slices are missing due to negative values
2. Shown as 0 values to force their inclusion in the legend.
3. Show it correctly if all of them are negative.

We should check in serialized results to the repo for past sybil versions and make sure that future sybil binaries are compatible with them