feat: Use the jemalloc global allocator in examples

Cargo.toml

@@ -41,9 +41,13 @@ nightly = ["hashbrown/nightly", "group-by/nightly"]
 [dev-dependencies]
 csv = "1.0"
 elapsed = "0.1"
+jemallocator = "0.1"
 quickcheck = "0.7"
 rand = "0.6"
 rand_xorshift = "0.1"
 structopt = "0.2"
 tempfile = "3.0"
 termcolor = "1.0"
+
+[profile.release]
+debug = true

README.md

@@ -32,6 +32,11 @@ We made some tests on remote machines and found that we can handle with a datase
 
 Network is mesured, servers are located in amsterdam and tests are made between two different datacenters.
 
+### Notes
+
+The default Rust allocator has recently been [changed to use the system allocator](https://github.com/rust-lang/rust/pull/51241/).
+We have seen much better performances when [using jemalloc as the global allocator](https://github.com/alexcrichton/jemallocator#documentation).
+
 
 
 ## Usage and examples

examples/create-database.rs

@@ -1,3 +1,6 @@
+#[global_allocator]
+static ALLOC: jemallocator::Jemalloc = jemallocator::Jemalloc;
+
 use std::path::{Path, PathBuf};
 use std::error::Error;
 use std::borrow::Cow;

examples/query-database.rs

@@ -1,3 +1,6 @@
+#[global_allocator]
+static ALLOC: jemallocator::Jemalloc = jemallocator::Jemalloc;
+
 use std::collections::btree_map::{BTreeMap, Entry};
 use std::iter::FromIterator;
 use std::io::{self, Write};