A 460MB CSV file was imported into both an OLAP database and a TSDB database with the same schema. The size of the OLAP database was 107M, but the siz ...
A 460MB CSV file was imported into both an OLAP database and a TSDB database with the same schema. The size of the OLAP database was 107M, but the siz ...
Suppose a database is defined with 1 million value-based partitions, but data is only imported into 10 partitions. In DolphinDB, actual partitions are ...
I have created a UDF and used it in a where clause, which is shown in the following figure. But an error is reported as follows: Why is that hap ...
I run the following script in Python: Output (of DataFrame type): If I run the script as follows: Output (of <class 'method'> data type ...
The following script defines a stream table where the column “askPrice“ and “bidPrice“ are array vectors of DOUBLE type. Script in Python: But a ...
When processing stream data with the reactive state engine, I want to count how many of the last ten rows have the same value as the current row. Is t ...
I create the following 3 mvcc tables Is there any way to automatically load all these tables when DolphinDB is started? ...
How to check the loaded modules in DolphinDB? Or, which command can be used to access the modules executed in the GUI or the startup script (startup.d ...
I have a table t For the missing values of the column price, like 102, 104, and 105, I want to fill it with n=0. ...
For example, I have an array data = 0 0 0 0 0 0 1 1 1. I want to get the index of the first non-zero element in the array. ...
My background job returns a table. How do I view this table? For example: ...
I have a table as follows: I want to query data with multiple field values. Query condition: field value “Id=1“, “area“ = A, F, G; field val ...
I have a DolphinDB table "t1". Now I want to append data.frame in R to "t1", how can I do? (Table schema cannot be taken into consideration. The numbe ...
When appending data to DolphinDB using Python API, I find it difficult to covert Python date, time and datetime objects into DolphinDB temporal types. ...
Reference: DolphinDB user manual. I have set up a cluster. I configured the logFile configuration parameter in the file controller.cfg to specify the ...
I have a table created with the following script: where ts is the time, status indicates the device status (0: down; 1: running), and val indicate ...
I use 2 different methods to query data in DolphinDB Python API. The first one uses the loadTableBySQL method, and the second uses the select method: ...
In DolphinDB, it seems I cannot specify a non-temporal column for the sortColumns of createPartitonedTable with the TSDB storage engine. Or is there a ...
I have a table as follows (just to give an example): The first column is the date column and the rest of columns store the data of yield. I want t ...
The following data is read from a CSV file of tick data. I have a column “quotes” of string type like this: For example, a value of field “quot ...