Trino Client - Metadata - Inspecting Catalogs

Overview #

The Trino client provides convenience methods for inspecting catalog metadata. Each method executes a SQL query internally and returns a simplified result — typically an array of strings or tuples.

See the API Reference for full method signatures and return types.

schemas #

Lists all schemas in a catalog.

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import { TrinoClient } from "@lakeql/trino-client"

const client = new TrinoClient({
  host: "https://trino.example.com",
  port: 8443,
  auth: { type: "basic", username: "analyst", password: "secret" },
  catalog: "hive",
})

const schemas = await client.schemas({ catalog: "hive" })
// ["default", "sales", "analytics", "information_schema"]

tables #

Lists all base tables in a catalog and schema.

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import { TrinoClient } from "@lakeql/trino-client"

const client = new TrinoClient({
  host: "https://trino.example.com",
  port: 8443,
  auth: { type: "basic", username: "analyst", password: "secret" },
  catalog: "hive",
})

const tables = await client.tables({ catalog: "hive", schema: "sales" })
// ["orders", "customers", "products", "invoices"]

views #

Lists all views in a catalog and schema.

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import { TrinoClient } from "@lakeql/trino-client"

const client = new TrinoClient({
  host: "https://trino.example.com",
  port: 8443,
  auth: { type: "basic", username: "analyst", password: "secret" },
  catalog: "hive",
})

const views = await client.views({ catalog: "hive", schema: "sales" })
// ["monthly_revenue", "top_customers"]

columns #

Lists all columns for a specific table, including their types and metadata.

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20import { TrinoClient } from "@lakeql/trino-client"

const client = new TrinoClient({
  host: "https://trino.example.com",
  port: 8443,
  auth: { type: "basic", username: "analyst", password: "secret" },
  catalog: "hive",
})

const columns = await client.columns({
  catalog: "hive",
  schema: "sales",
  table: "orders",
})
// [
//   ["id", "varchar", "", "Order identifier"],
//   ["amount", "double", "", "Total order amount"],
//   ["created_at", "timestamp(3)", "", "When the order was placed"],
// ]

Typed objects with `asObject` #

Pass asObject: true to get ColumnInfo[] objects instead of raw tuples:

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24import { TrinoClient } from "@lakeql/trino-client"

const client = new TrinoClient({
  host: "https://trino.example.com",
  port: 8443,
  auth: { type: "basic", username: "analyst", password: "secret" },
  catalog: "hive",
})

const columns = await client.columns({
  catalog: "hive",
  schema: "sales",
  table: "orders",
  asObject: true,
})
// [
//   { name: "id", type: "varchar", extra: "", description: "Order identifier" },
//   { name: "amount", type: "double", extra: "", description: "Total order amount" },
// ]

for (const col of columns) {
  console.log(`${col.name}: ${col.type}`)
}

Full Discovery Example #

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28import { TrinoClient } from "@lakeql/trino-client"

const client = new TrinoClient({
  host: "https://trino.example.com",
  port: 8443,
  auth: { type: "bearer", token: "eyJhbGciOiJSUzI1NiIs..." },
  catalog: "iceberg",
})

// Discover all tables across all schemas
const schemas = await client.schemas({ catalog: "iceberg" })

for (const schema of schemas) {
  if (schema === "information_schema") {
    continue
  }

  const tables = await client.tables({ catalog: "iceberg", schema })
  console.log(`${schema}: ${tables.join(", ")}`)

  for (const table of tables) {
    const columns = await client.columns({ catalog: "iceberg", schema, table })
    console.log(
      `  ${table}: ${columns.map(([name, type]) => `${name} (${type})`).join(", ")}`
    )
  }
}