query speed issue -- 1.7 million records take over 50 mins

on Azure Synapse, we are trying to query cosmosDB (collection contains 1.7 million records) using AzureCosmosR library. To get 1.7 million records (with a partition_key) is taking over 50 min consistently.
 
Steps -
 
devtools::install_github("Azure/AzureCosmosR")
library(AzureCosmosR)
 
endp <- cosmos_endpoint(
    "[https://xxxxxxx.documents.azure.com:443/"](https://xxxxxxx.documents.azure.com/%22),
    key="xxxxxxxxxxxxxxxxxxx"
)
# all databases in this account
list_cosmos_databases(endp)
 

db <- get_cosmos_database(endp, "internal")
# get a specific container - user, event, message, chat etc
container <- get_cosmos_container(db, "message", partition_key="id")
 

df_lst <- query_documents(container,
    "SELECT * FROM container c")
 
 
Are there any optimizations that can be done to fix the slowness of reading the records from cosmosDB account?