SQL Server (MSSQL)

SQL Server datasources use the ODBC driver and Microsoft ODBC Driver 18 for SQL Server.

See Supported Data Formats for database source categories and schema column types supported on SQL Server connections.

Connection configuration

URI format

mssql://user:password@host:1433/database

Required fields

Field	Type	Description
`connection_type`	string	Must be `"mssql"`
`connection_sub_type`	string	Must be `"database"`
`uri`	string	SQL Server connection string
`server`	string	Database host address
`database`	string	Database name
`username`	string	Database user
`password`	string	Database password

Optional fields

Field	Type	Default	Description
`encryption`	string		TLS encryption mode (e.g., `"yes"`, `"no"`, `"strict"`)

Environment variables

Variable	Description
`ODBC_MSSQL_DRIVER`	Override the ODBC driver name (default: `"ODBC Driver 18 for SQL Server"`)
`GODEBUG`	Set to `x509negativeserial=1` for servers using older certificates with negative serial numbers

The ODBC_MSSQL_DRIVER environment variable allows you to use a different version of the Microsoft ODBC driver (e.g., Driver 17) without modifying the connection configuration.

Example connection

{
  "name": "mssql-market-data",
  "connection_type": "mssql",
  "connection_sub_type": "database",
  "uri": "mssql://libuser:s3cureP@ss@db.example.com:1433/marketdata",
  "server": "db.example.com",
  "database": "marketdata",
  "username": "libuser",
  "password": "s3cureP@ss",
  "encryption": "yes"
}

Dataset configuration (data_args)

Required fields

Field	Type	Description
`table_options`	list	Tables to query (see below)
`database`	string	Connection reference name
`data_dt_column`	string or list	Column(s) containing the datetime value
`data_dt_format`	bool or string or list	`true` for native datetime auto-detect, or strptime format
`data_dt_timezone`	string	Timezone of the source data
`data_key_column`	string or list	Column(s) used as the symbol/key for query filtering

Optional fields

Field	Type	Default	Description
`batch_size`	int	`10000`	Number of rows per query batch
`data_dt_nudge`	int	`0`	Microsecond offset applied to timestamps

table_options entry

Each entry in table_options describes a table to query:

Field	Type	Description
`db`	string	Database name
`table_like`	string	Table name or pattern
`token`	string	Table identifier token
`zone`	string	Timezone, default `"America/New_York"`
`dt_mode`	string	(Optional) Datetime mode
`dt_regex`	string	(Optional) Regex for partitioned tables
`dt_format`	string	(Optional) Datetime format for partitioned tables
`nudge_micros`	int	(Optional) Microsecond nudge

Complete example

Connection

{
  "name": "mssql-trades",
  "connection_type": "mssql",
  "connection_sub_type": "database",
  "uri": "mssql://libuser:s3cureP@ss@sqlserver.example.com:1433/trades_db",
  "server": "sqlserver.example.com",
  "database": "trades_db",
  "username": "libuser",
  "password": "s3cureP@ss",
  "encryption": "yes"
}

Dataset

{
  "name": "us-equity-trades",
  "connection": "mssql-trades",
  "data_args": {
    "table_options": [
      {
        "db": "trades_db",
        "table_like": "daily_trades",
        "token": "daily_trades",
        "zone": "America/New_York"
      }
    ],
    "database": "mssql-trades",
    "batch_size": 10000,
    "data_dt_column": "trade_time",
    "data_dt_format": true,
    "data_dt_timezone": "America/New_York",
    "data_dt_nudge": 0,
    "data_key_column": "symbol"
  },
  "schema": [
    { "name": "symbol", "type": "string", "group": "key", "description": "Ticker symbol" },
    { "name": "trade_time", "type": "string", "group": "time", "description": "Trade timestamp" },
    { "name": "price", "type": "double", "group": "value", "description": "Trade price" },
    { "name": "volume", "type": "int64", "group": "value", "description": "Trade volume" },
    { "name": "exchange", "type": "string", "group": "value", "description": "Exchange code" }
  ]
}

Set data_dt_format to true when using native SQL Server datetime2 or datetimeoffset columns. CloudQuant Data Liberator will auto-detect the datetime type and convert directly without string parsing.

Encryption configuration

SQL Server connections support several TLS encryption modes via the encryption field:

Value	Description
`"yes"`	Require encrypted connection (recommended)
`"no"`	Do not encrypt the connection
`"strict"`	Strict TLS 1.2+ encryption (SQL Server 2022+)

When using encryption: "yes" with self-signed certificates, you may need to add TrustServerCertificate=yes to the connection. For production, always use properly signed certificates.

Legacy certificate support

For SQL Server instances using older certificates with negative serial numbers:

export GODEBUG=x509negativeserial=1

This is common with older SQL Server installations that have not rotated their TLS certificates.

Driver and dependencies

Component	Details
Driver	`ODBC driver` with ODBC Driver 18 for SQL Server
Protocol	ODBC / TDS
Arrow conversion	High-performance ODBC driver
ODBC required	Yes (Microsoft ODBC Driver 18)
Default port	1433

The Microsoft ODBC Driver 18 must be installed on the CloudQuant Data Liberator host. To use a different driver version, set the ODBC_MSSQL_DRIVER environment variable.

Troubleshooting

ODBC driver not found

Verify the Microsoft ODBC Driver 18 is installed and registered:

# List installed ODBC drivers
odbcinst -q -d

# Expected output should include:
# [ODBC Driver 18 for SQL Server]

Install the driver if missing:

curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add -
curl https://packages.microsoft.com/config/ubuntu/22.04/prod.list > /etc/apt/sources.list.d/mssql-release.list
apt-get update && ACCEPT_EULA=Y apt-get install -y msodbcsql18

curl https://packages.microsoft.com/config/rhel/8/prod.repo > /etc/yum.repos.d/mssql-release.repo
ACCEPT_EULA=Y yum install -y msodbcsql18

Using a different driver version

Override the default driver with an environment variable:

export ODBC_MSSQL_DRIVER="ODBC Driver 17 for SQL Server"

Certificate errors (x509)

If you see x509: certificate signed by unknown authority or negative serial number errors:

export GODEBUG=x509negativeserial=1

Connection timeout

SQL Server may be configured to listen on a non-default port or require a named instance. Verify connectivity:

# Test port connectivity
nc -zv sqlserver.example.com 1433

# For named instances, use the SQL Browser port (1434/UDP) or specify the port directly

Windows authentication

CloudQuant Data Liberator uses SQL Server authentication (username/password). Windows/Kerberos authentication is not supported through this connection type.

Slow queries

Increase batch_size for large result sets (up to 100000).
Ensure the datetime and key columns are indexed.
For partitioned tables, use dt_regex to scope queries to relevant partitions.
Consider using datetime2 over datetime for better precision and performance.

​SQL Server (MSSQL)

​Connection configuration

​URI format

​Required fields

​Optional fields

​Environment variables

​Example connection

​Dataset configuration (data_args)

​Required fields

​Optional fields

​table_options entry

​Complete example

​Connection

​Dataset

​Encryption configuration

​Legacy certificate support

​Driver and dependencies

​Troubleshooting

​ODBC driver not found

​Using a different driver version

​Certificate errors (x509)

​Connection timeout

​Windows authentication

​Slow queries

SQL Server (MSSQL)

Connection configuration

URI format

Required fields

Optional fields

Environment variables

Example connection

Dataset configuration (data_args)

Required fields

Optional fields

table_options entry

Complete example

Connection

Dataset

Encryption configuration

Legacy certificate support

Driver and dependencies

Troubleshooting

ODBC driver not found

Using a different driver version

Certificate errors (x509)

Connection timeout

Windows authentication

Slow queries